Rectum. Rectum topography. Walls, relation to the peritoneum of the rectum. What is the structure of the rectum in women and men? Rectal folds

The rectum is a "straight" organ in lower mammals - hence its Latin name. However, in humans, it bends, adjacent to the sacral cavity, starting at the promontory of the sacrum and ending below the coccyx. The relationship of the rectum with the anal canal is of paramount importance, since the work of the sphincter apparatus, which controls the evacuation of feces, is provided by nerves located in the danger zone, which can be damaged during surgical interventions in the depth of the pelvis. The rectum is located deep in the pelvis, is in close contact with many vital organs, and therefore operations on it are extremely difficult. Especially great difficulties arise when it is necessary to restore intestinal continuity, since the operation takes place in a confined space.

The rectum extends from the sigmoid colon to the anus and has a length of 12-16 cm. There are two main sections of the rectum: pelvic and perineal. The first lies above the pelvic diaphragm, the second below. In the pelvic region, an ampoule is isolated and a small area above it - the supra-ampullary part. The perineum of the rectum is also called the anal canal.

The supra-ampullary part of the intestine is covered by the peritoneum from all sides. Further, the intestine begins to lose the peritoneal cover, first from behind, being covered by the peritoneum only in front and from the sides, and even lower, at the level of the 4th sacral vertebra (and partly the 5th), the peritoneum covers only the anterior surface of the intestine and passes to the posterior surface in men Bladder. The lower part of the rectal ampulla lies under the peritoneum.

The rectal mucosa has longitudinal folds, which are often called morgan columns. Between them are the anal (Morgan) sinuses, bounded from below by the semilunar anal flaps. The transverse folds of the mucous membrane, which do not disappear when the rectum is filled, are located in different parts of it. One of them corresponds to position n. sphincter tertius and is located on the border between the ampullary and nadampular parts of the intestine. The intestinal mucosa forms folds: closer to the anus - longitudinal, and above - transverse. In the ampullar part there is one fold on the right wall, two on the left. On the border of the ampullar and anal parts of the rectum, according to the position of the internal sphincter, there is a well-pronounced fold, especially on the posterior wall of the intestine, - valvula Houstoni. When the intestine is full, these folds can expand and increase its volume.

At a distance of 3-4 cm from the anus, the annular muscle fibers, thickening, form an internal sphincter, and at a distance of about 10 cm from the anus there is another thickening of the annular muscle fibers, known as the Hepner muscle (m.sphincter tertius). The external press of the rectum is located in the circumference of the anus and consists of striated muscle fibers (Fig. 193).

The blood supply to the rectum is carried out by 5 arteries: one unpaired - a. rectales superior (terminal branch of the inferior mesenteric artery) and two paired - a. rectales media (branch a. iliaca interna) and a. rectalis inferior (branch a.pudenda interna) (Fig. 194).

The veins of the rectum (Fig. 195) belong to the systems of the inferior vena cava and portal veins and form a plexus, which is located in different layers of the intestinal wall. Distinguish between external and internal hemorrhoidal plexus. The external plexus is located under the skin of the anus, in the circumference and on the surface of the external press of the rectum. The submucosal plexus, the most developed, is located in the submucosa; it can be divided into three sections: upper, middle, lower. In the final section of the rectum, the veins of the submucosal plexus have a special - cavernous structure. The subfascial plexus lies between the longitudinal muscle layer and the fascia of the rectum. In the area of the rectum between the longitudinal folds and the anus - zona hemmoroidalis (venous ring) - the submucosal plexus consists of tangles of veins that penetrate between the bundles of circular. The outflow of venous blood from the rectum is carried out through the rectal veins, of which the upper one is the beginning of the inferior mesenteric and belongs to the portal vein system, and the middle and lower ones belong to the inferior cavity system: the middle ones flow into the internal iliac veins, and the lower ones - into the internal pudendal veins (Fig. . 195).

Rice. 193. Rectum anatomy. 1 - middle transverse fold (valvula Houstoni); 2 - upper transverse fold (valvula Houstoni); 3 - muscle lifting the anus (m. Levator ani); 4 - lower transverse fold (valvula Houstoni); 5 - anal (anal) columns (Morgani); 6 - jagged line; 7 - internal hemorrhoidal plexus; 8 - anal gland; 9 - internal anal sphincter; 10 - external hemorrhoidal plexus; 11 - anal crypts; 12 - external anal sphincter

Rice. 194. Blood supply to the rectum. 1 - inferior mesenteric artery; 2 - sigmoid arteries; 3 - mesentery of the sigmoid colon; 4 - superior rectal artery; 5 - superior rectal artery (branching); 6 - internal genital artery; 7 - lower rectal artery; 8 - internal iliac artery; 9 - obturator artery; 10 - median sacral artery; 11 - superior cystic artery; 12 - lower cystic artery; 13 - middle rectal artery; 14 - superior rectal artery

Rice. 195. Rectal veins. 1 - inferior vena cava; 2 - common iliac veins; 3 - median sacral vein; 4 - inferior mesenteric vein; 5 - sigmoid veins; 6 - superior rectal vein; 7 - external iliac vein; 8 - internal iliac vein; 9 - obturator vein; 10 - gallbladder (upper) and uterine veins; 11 - middle rectal vein; 12 - internal genital vein; 13 - portocaval anastomoses; 14 - lower gallbladder veins; 15 - internal genital vein; 16 - lower rectal vein; 17 - venous plexus of the rectum; 18 - external hemorrhoidal plexus; 19 - internal hemorrhoidal plexus

The innervation of the rectum is carried out by sympathetic, parasympathetic and sensory fibers. Lymphatic vessels accompany arterial. Lymphatic drainage is carried out from the upper and middle sections of the rectum to the lower mesenteric nodes, and from the lower section to the lower mesenteric and / or iliac and periaortic nodes. Below the dentate line, lymphatic drainage occurs into the iliac nodes.

To successfully perform pelvic surgery, knowledge of the detailed anatomy of the mesorectum and its contents in adults is essential.

Mesorectum (a collection of tissues located between the wall of the rectum and its visceral fascia) is not described as an identifiable structure in most works on human anatomy, although it is mentioned by many embryologists.

The mesorectum originates from the dorsal mesentery, the common visceral mesentery that surrounds the rectum, and is covered by a layer of visceral fascia that provides a relatively bloodless layer, the so-called "holy plane" mentioned by Heald. The goal of the surgical intervention is to gain access while remaining in this fascial layer. Behind this layer passes between the visceral fascia surrounding the mesorectum and the parietal presacral fascia (Fig. 196). The last layer is commonly referred to as Valdeyer's fascia. Below, at the S4 level, these fascial layers (mesorectal and Waldeyer) are combined to form the rectosacral ligament, which must be divided when the rectum is mobilized.

A more accurate understanding of the rectum, mesorectum, innervation and vascularization of them and the surrounding structures has appeared recently. New developments in imaging techniques such as endorectal ultrasound (ERUS) and magnetic resonance imaging (MRI) will undoubtedly shed light on the “normal” anatomy of these structures.

Rice. 196. Mesorektum. 1 - mesorectum; 2 - lymph nodes; 3 - visceral fascia; 4 - rectal lumen. T - tumor growing into the mesorectum

What is Hemorrhoids

Hemorrhoids - a pathological increase in the cavernous vascular plexus with the formation of hemorrhoids, their prolapse from the anal canal with periodic bleeding and frequent inflammation. According to various authors, this disease affects up to 10-15% of the adult population. The proportion of hemorrhoids in the structure of coloproctological diseases is 35–40%. From 10 to 60% of patients with this disease seek medical help. Many patients self-medicate for a long time and seek help only with the development of various complications that they cannot cope with on their own.

Translated from Greek, the word "hemorrhoids" means bleeding, and it is the main symptom of this disease. Hemorrhoids are one of the most ancient human diseases. As early as 2 thousand years BC, in Egypt, hemorrhoids were known and isolated as a separate disease. Doctors of that time even tried to operate on patients with hemorrhoids, removing hemorrhoids that fell out of the anus. The symptoms of this disease are mentioned in the works of Hippocrates, who wrote that hemorrhoids are associated with frequent constipation, so that people who consume a lot of strong drinks and spicy foods are more susceptible to this disease.

Only in the 18th century were cavernous formations found in the distal part of the rectum. The mechanisms of the pathogenesis of hemorrhoids were studied much later, after a hundred years, a great contribution to this was made by the famous Russian surgeons N.V. Sklifosovsky, A.V. Starkov, P.A.Butkovsky and A.N. Ryzhikh.

In the 30s of the XX century, for the treatment of hemorrhoids, Milligan and Morgan proposed an operation - hemorrhoidectomy. Its various modifications are still in use.

Etiology and pathogenesis

Hemorrhoids are nothing more than an increase in the size of the cavernous submucosal plexuses of the rectum. These plexuses represent arteriovenous anastomoses and are located in typical places - at 3, 7 and 11 o'clock (in the patient's supine position), respectively, to the three terminal branches of the division of the superior rectal artery (Fig. 197).

Rice. 197. Localization of hemorrhoids. 1 - on the back-side wall (at 7 o'clock on the dial); 2 - on the anterolateral (at 11 o'clock); 3 - on the side wall (at 3 o'clock); 4 - superior rectal artery

The cavernous plexus is not a pathology, but normal cavernous vascular formations that form during normal embryogenesis and are present in people of any age, including embryos and children. In children, the cavernous formations of the rectum are poorly developed, their sizes are small, the cavernous cavities (sinuses) are indistinct. With age, the size of the sinuses and individual cavernous plexuses increase and this is the anatomical substrate of the future main internal hemorrhoids. The hemorrhoidal plexus is an important anatomical structure that plays a decisive role in the so-called "thin" anal stool retention. Due to their elastic consistency, there is a delay in the venous outflow of blood under tension m. sphinkter ani internus. All this makes it possible to retain solid components of feces, air and liquid in the ampulla of the rectum. Relaxation of the sphincter during bowel movements leads to the outflow of blood from the hemorrhoidal plexus and emptying of the rectal ampulla. It should be noted that this physiological mechanism is carried out during the formation of normal feces. Too hard stool masses inhibit the urge to defecate, while the hemorrhoidal plexus is filled with blood much longer. Subsequently, their pathological expansion and further transformation into hemorrhoids occurs. On the other hand, liquid stool also stimulates too frequent emptying of the rectum, which usually occurs against the background of an incompletely relaxed sphincter and still crowded hemorrhoidal plexuses. Their constant trauma arises, which ultimately leads to secondary changes, that is, to the formation of hemorrhoids. Of great importance in the development of hemorrhoids is the disturbed relationship between the inflow and outflow of blood from the corpora cavernosa. Factors such as pregnancy and childbirth, obesity, excessive alcohol and coffee abuse, chronic diarrhea, sedentary, sedentary lifestyle, straining during bowel movements, smoking, heavy lifting, prolonged coughing lead to increased intra-abdominal pressure and blood stagnation in the small pelvis. Hemorrhoids increase in size. The development of dystrophic processes in the common longitudinal muscle of the submucous layer of the rectum and Parks ligament, which hold the cavernous bodies in the anal canal, leads to a gradual but irreversible displacement of hemorrhoids in the distal direction and their subsequent loss from the anal canal.

Classification

By etiology:

1) congenital (or hereditary);

2) acquired: primary or secondary (symptomatic). By localization (Fig. 198):

1) external hemorrhoids (subcutaneous);

2) internal hemorrhoids (submucosal);

3) combined.

According to the clinical course:

1) sharp;

2) chronic.

Allocate 4 stages of chronic hemorrhoids:

Stage I manifested by bleeding, hemorrhoids do not fall out.

Stage II- hemorrhoids fall out when straining and set on their own.

Stage III- hemorrhoids fall out and are set only manually. Moreover, first nodes fall out only during bowel movements, then with an increase in intra-abdominal pressure.

Stage IV- hemorrhoids fall out and at rest, do not adjust or fall out again immediately after reduction.

In addition, there are three severity acute hemorrhoids:

I degree- external hemorrhoids of small size, tight-elastic consistency, painful on palpation, the perianal skin is slightly hyperemic, patients experience a burning sensation and itching, aggravated by defecation.

II degree- Characterized by pronounced edema of most of the perianal region and its hyperemia, pain on palpation and digital examination of the rectum, severe pain in the anus, especially when walking and sitting.

Rice. 198. Localization of hemorrhoids. 1 - internal; 2 - external

III degree- the entire circumference of the anus is involved in an inflammatory infiltrate, palpation is sharply painful, purple or bluish-purple internal hemorrhoids covered with fibrin are visible in the anus. If untreated, nodule necrosis may occur. Clinical picture and data of objective research

Complaints. The patient has complaints, as a rule, when complications of hemorrhoids occur - thrombosis of hemorrhoids or bleeding from these nodes. In this case, patients are worried about the prolapse or protrusion from the anus of a dense, painful node (with thrombosis), the presence of scarlet blood in the stool (with bleeding) - from small drops and veins to profuse bleeding. These complaints, as a rule, are associated with the act of defecation and are accompanied by a feeling of discomfort, bloating or even pain in the anus, anal itching - the latter often precedes episodes of bleeding. The listed symptoms are especially aggravated after the intake of abundant spicy food, which is due to blood congestion in the pelvic area.

With external hemorrhoids, hemorrhoidal plexuses are located distal to the dentate line, in the anal canal lined with anoderm. Together with the adjacent skin, it is innervated by somatic sensory nerves, which have nociception (the physiological ability to perceive and transmit pain), which is the cause of severe pain in the anus during exacerbation of external hemorrhoids and interventions in this area. With internal hemorrhoids, the nodes are located proximal to the dentate line of the anal canal, under the mucous membrane, which is innervated by autonomic nerves and is relatively insensitive to pain. All this explains the painless course of internal hemorrhoids.

When collecting anamnesis, you can trace a certain sequence of the appearance of complaints. One of the first symptoms is anal itching. Bleeding usually occurs later. The resulting bleeding is often persistent, prolonged and intense, sometimes leading to severe anemia. Subsequently, patients begin to notice protrusion and loss of nodes, often with a tendency to inflammation or infringement.

It is also necessary to keep in mind the diseases that cause secondary hemorrhoids (portal hypertension, pelvic tumors, etc.).

An objective examination of the patient begins with an examination of the anal area. In this case, you can see enlarged, collapsed or compacted and inflamed hemorrhoids at 3, 7 and 11 hours (Fig. 199). In some patients, the nodes are not clearly grouped in the indicated places, which indicates the loose nature of the cavernous bodies of the rectum. Internal knots can resemble "mulberry" and bleed easily on contact. When straining the patient, the nodes can protrude outward. With a digital examination, hemorrhoids can be identified, which become dense and sharply painful during an exacerbation. Therefore, with obvious thrombosis of hemorrhoids, digital examination should be carried out with extreme caution or even refrain from it. With long-term hemorrhoids, even a decrease in the tone of the rectal closure apparatus may develop.

It is mandatory to carry out sigmoidoscopy, allowing to assess the form and stage of the pathological process. In addition, it is necessary to examine the superior parts of the rectum and exclude other diseases, in particular the tumor process.

For this, an irrigoscopy and / or fibrocolonoscopy should be performed. Differential diagnosis

First of all, it is necessary to exclude colon tumors, as well as inflammatory diseases or diverticulosis of the colon in which there is a discharge of blood from the rectum. In this case, special attention should be paid to the presence of such alarming symptoms in the patient as the presence of alternating constipation and diarrhea, bloating, recurrent cramping pains in the abdomen, the appearance of pathological impurities (mucus, blood) in the feces, weight loss, fever, anemia, etc. In addition, rectal bleeding can also be caused by adenomatous polyps, ulcers, and fissures in the anus.

Itching in the anus can also occur with helminthiasis, contact dermatitis, and insufficient hygiene of the anorectal region. Pain during defecation or palpation of hemorrhoids can be a sign of not only thrombosis of external hemorrhoids, but also cracks in the anus (it can be a concomitant disease in 20% of people with hemorrhoids) or a perianal (intersphincteric) abscess.

In addition, as already indicated, portal hypertension may be the cause of rectal varicose veins.

Complications

1. Bleeding. It occurs with thinning of the mucous membrane over the hemorrhoid, while blood is poured out of erosion or diffusely. It is fresh and liquid. Blood appears on toilet paper or drips from the anus after a bowel movement. Patients note such bleeding periodically, more often it is observed with constipation. In rectal cancer or ulcerative colitis, blood in the stool is observed in any stool (not necessarily dense), in tenesmus it is mixed with feces, and in hemorrhoids, blood covers the stool. Repeated, even minor, hemorrhoidal bleeding, as already noted, can lead to anemia.

2. Inflammation. With inflammation, internal hemorrhoids are red, enlarged, painful, bleeding from superficial erosions. Reflex spasms of the anus occur, digital examination is painful.

3. Thrombosis of internal hemorrhoids arises suddenly: one of the nodes becomes significantly enlarged, purple, very painful on palpation and defecation. The acute condition lasts 3-5 days, after which the node undergoes connective tissue changes. Then, during rectal examination, it is palpated in the form of a dense nodule.

4. Prolapse of hemorrhoids. If the internal hemorrhoids reach large sizes, then they go beyond the anorectal line and appear in front of the anus, either only when straining (descending hemorrhoids), or constantly (falling hemorrhoids).

Hemorrhoids can be treated conservatively and surgically.

Diet. With hemorrhoids, it is necessary to eat regularly, at the same time, eat more vegetable fiber against the background of increased water consumption (1.5-2 liters per day). It is necessary to limit products from white refined flour, whole milk, while fermented milk products can and should be consumed daily, especially those enriched with bifidobacteria and lactobacilli. Strengthens intestinal motility by drinking mineral waters. Highly and moderately saline waters are recommended, as well as waters containing magnesium ions and sulfates, such as "Essentuki", "Moskovskaya". It is necessary to exclude alcoholic beverages, as well as spicy, spicy, fried, smoked foods, since the use of these products leads to an increase in blood flow in the perianal region and blood stagnation in the pelvic region.

The tasks that drug therapy should solve are as follows: relief of pain syndrome, hemorrhoidal thrombosis, elimination of the inflammatory process and prevention of repeated exacerbation of hemorrhoids. When choosing a local treatment for acute hemorrhoids, it is necessary to take into account the prevalence of any of the symptoms. In case of bleeding, the amount of blood loss, its intensity and severity of post-hemorrhagic anemia should be assessed. It should be noted that the prevention of exacerbation, first of all, consists in the normalization of the activity of the digestive tract, the treatment of constipation, which occurs in more than 75% of patients with hemorrhoids. Increased intake of fiber and fluid leads to a softening of feces, prevention of constipation and a decrease in the duration and intensity of straining during bowel movements. The optimal dose of insoluble fiber is 25–30 g per day. You can get it by eating fiber-rich foods such as breakfast cereals, wholemeal breads, brown rice and wholemeal pasta, fruits, vegetables, and salads (vegetables and fruits - at least three servings daily), and legumes (lentils, beans, peas, etc.). If diet therapy is ineffective, laxatives should be used (for example, fibodel, regulan, normacol, normacol-plus, methyl cellulose).

The indication for conservative treatment is the initial stage of chronic hemorrhoids. It consists of general and local use of pain relievers and anti-inflammatory drugs, cleansing enemas, ointment dressings and physiotherapy.

To eliminate the pain syndrome, the use of non-narcotic analgesics and local combined anesthetic drugs in the form of gels, ointments and suppositories is shown. For local therapy, drugs such as aurobin, ultraproct, proctoglyvenol, etc. are used. In addition, new pain relievers nefluan and emla, which have a high concentration of lidocaine and neomycin, are effective.

Combined preparations containing painkillers, thrombolytic and anti-inflammatory components are indicated for thrombosis of hemorrhoids complicated by their inflammation. This group of drugs includes proctosedil and hepatothrombin G, produced in the form of ointment, gel bases and suppositories. The pharmacokinetics of the latter drug is that heparin and allantoin, binding plasma coagulation factors and exerting an inhibitory effect on hemostasis, cause a thrombolytic effect, and panthenol stimulates metabolic processes, granulation and epithelization of tissues. Polidocanol, which is part of it, provides an analgesic effect. For the relief of inflammation, in addition to local treatment, non-steroidal anti-inflammatory drugs are used that have a combined effect, including analgesics (ketoprofen, diclofenac, indomethacin, etc.).

The basis of general treatment is the use of phlebotropic drugs that affect the increase in venous tone, improve microcirculation in the cavernous bodies and normalize blood flow in them. This group includes drugs such as escin, tribenoside, troxerutin, as well as new generation drugs: Detralex, Cyclo-3 Forte, Ginkor-Forte, Endothelon, etc.

If conservative treatment is ineffective, especially in the later stages of the disease, a combination treatment should be carried out, including conservative and minimally invasive methods or conservative and surgical methods.

There are the following main types of minimally invasive hemorrhoid interventions: injection sclerotherapy, infrared coagulation, latex ring ligation, cryotherapy, diathermic coagulation, bipolar coagulation.

At the first stage of hemorrhoids, sclerotherapy has proved to be quite effective. A sclerosing drug (ethoxysclerol, thrombovar, fibrovein) is injected circularly subcutaneously just above the dentate line. As a rule, 1 ml of sclerosing agent is enough, the procedure is repeated 2-3 times within two weeks. For sclerosing according to Blanchard (Fig. 200), a solution of sclerosant is injected directly into the region of the vascular pedicle of the hemorrhoid in typical places (3, 7, 11 hours).

Rice. 200. Injection of a sclerosant into the region of the vascular pedicle of the hemorrhoid (according to Blanchard)

The therapeutic effect is not in violation of the blood supply to hemorrhoids, as previously assumed, but in their fixation above the dentate line. The advantage of sclerotherapy is in a fairly low level of postoperative complications. The main drawback limiting the use of this minimally invasive technique is a high relapse rate - up to 70% three years after therapy. An effective method, especially shown for bleeding hemorrhoids in stage I, is infrared coagulation of hemorrhoids. The therapeutic effect is based on the stimulation of mucosal necrosis by thermocoagulation.

The technique of ligating enlarged hemorrhoids (optimally carried out at stage II of the disease) using a rubber ring, leading to their necrosis and rejection, was proposed in 1958 by R. S. Blaisdell, and later simply improved and simplified by J. Barron (1963) ... Currently, this method of treating hemorrhoids is effectively used by many proctologists (Fig. 201).

Operative treatment carried out in patients with stage III and IV of the disease.

Rice. 201. Ligation of internal hemorrhoids. A - seizure of the hemorrhoid with a clamp; B - dumping the latex ring onto the neck of the knot; B - the leg of the node is ligated. 1 - internal hemorrhoidal node; 2 - ligator; 3 - latex ring; 4 - clamp

The most common method at present is the Milligan-Morgan hemorrhoidectomy, which gives good results. The essence of the operation consists in excision of hemorrhoids from outside to inside with ligation of the vascular pedicle of the node, cutting off the node. As a rule, three external and three internal nodes corresponding to them are excised at 3, 7, 11 o'clock, with the obligatory leaving of mucous membrane jumpers between them in order to avoid narrowing of the anal canal. Three modifications of the operation are applied:

Closed hemorrhoidectomy with restoration of the anal mucosa with sutures (Fig. 202);

Open - leaving an unstitched wound (in case of danger of narrowing of the anal canal and with complications such as anal fissure, paraproctitis) (Fig. 203);

Under the mucous hemorrhoidectomy (from under the mucous layer with a high-frequency coagulator, the node is removed in a sharp way, leaving the stump of the node in the submucosal layer under the sutured mucosa. Italian Antonio Longo has developed a fundamentally new approach to surgical intervention for hemorrhoids.The essence of the operation is to perform circular resection and suturing prolapsed mucosa with hemorrhoids.During the Longo operation, only a part of the rectal mucosa, which is located above the dentate line, is removed.

Rice. 202. Closed hemorrhoidectomy. A - excision of the hemorrhoid;

B - wound of the anal canal after removal of the node;

B - suturing the wound of the anal canal with a continuous suture

Rice. 203. Open hemorrhoidectomy. The anal canal wound remains open

The defect of the mucous membrane is sutured using a circular stapler in an end-to-end manner. As a result, hemorrhoids are not removed, but are pulled up and sharply reduced in volume due to a decrease in blood flow to the cavernous bodies. As a result of excision of the circular strip of mucous membrane, conditions are created under which the blood supply to the nodes decreases, which leads to their gradual desolation and gobliteration.

Rice. 204. Operation Longo. A - the imposition of a circular purse-string suture on the mucous membrane of the rectum above the hemorrhoid; B - tightening the purse string suture between the head and the base of the stapler; B - the appearance of the anal canal after suturing the mucous membrane, hemorrhoidal vessels and tightening the hemorrhoids

The prognosis for hemorrhoids is usually favorable. The use of conservative therapy, minimally invasive methods, both independently and in combination with each other or with surgical methods, can achieve good results in 85–90% of patients.

Acute paraproctitis

Acute paraproctitis is an acute purulent inflammation of the peri-rectal intestinal tissue. In this case, the infection penetrates into the tissues of the near-rectal region from the lumen of the rectum, in particular from the anal crypts and anal glands.

Paraproctitis ranks 4th in frequency after hemorrhoids, anal fissures and colitis (up to 40% of all rectal diseases). Men suffer from paraproctitis more often than women. This ratio ranges from 1.5: 1 to 4.7: 1.

Etiology and pathogenesis

As already noted, acute paraproctitis occurs as a result of infection in the pararectal tissue. The causative agents of the disease are Escherichia coli, Staphylococcus aureus, Gram-negative and Gram-positive bacilli. Most often, polymicrobial flora is detected. Inflammation caused by anaerobes is accompanied by especially severe manifestations of the disease - gas phlegmon of the pelvic tissue, putrefactive paraproctitis, anaerobic sepsis. The causative agents of tuberculosis, syphilis, actinomycosis are very rarely the cause of specific paraproctitis.

The routes of infection are varied. Microbes enter the pararectal tissue from the anal glands that open into the anal crypts. As a result of the inflammatory process in the anal gland, its duct is blocked, an abscess is formed in the intersphincter space, which breaks into the perianal or pararectal space. The transition of the process from the inflamed gland to the pararectal tissue is also possible by the lymphogenous pathway. In the development of paraproctitis, a certain role can be played by trauma to the rectal mucosa by foreign bodies contained in feces, hemorrhoids, anal fissures, ulcerative colitis, Crohn's disease. Paraproctitis can be secondary. In this case, the inflammatory process passes to pararectal tissue from the prostate gland, urethra, and female genital organs. Rectal trauma is a rare cause of post-traumatic paraproctitis. The spread of pus along the pararectal cellular spaces can go in different directions, which leads to the formation of various forms of paraproctitis.

Classification

On the etiological basis, paraproctitis is divided into banal, specific and post-traumatic.

By the activity of the inflammatory process - on acute, infiltrative and chronic (rectal fistulas).

According to the localization of abscesses, infiltrates, leaks - on the subcutaneous, submucosal, intermuscular (when the abscess is located between the internal and external sphincter), sciatic-rectal (ischiorectal), pelvic-rectal (pelviorectal), posterior rectal (one of the types of rice . 205).

Can be distinguished 4 degrees of difficulty acute paraproctitis.

Paraproctitis of the 1st degree of complexity includes subcutaneous, submucosal, ischiorectal forms with intrasphincter communication with the rectal lumen, intermuscular (intersphincteric) paraproctitis.

To the II degree of complexity - ischio-, retrorectal forms of paraproctitis with transsphincteric communication through the superficial portion of the anal pulp (less than 1/2 portion, that is, less than 1.5 cm).

Paraproctitis of the III degree of complexity includes the forms as in the II degree, but with leaks, pelviorectal paraproctitis with the capture of 1/2 portion of the anal pulp (more than 1.5 cm thick), recurrent forms.

Paraproctitis IV degree of complexity includes all forms (ischio-, retro-, pelviorectal) with extrasphincteric course, with multiple leaks, anaerobic paraproctitis.

Rice. 205. Localization options for abscesses: 1 - subcutaneous; 2 - intermuscular;

3 - ishiorectal; 4 - pelviorectal.

Subcutaneous, ischeorectal and pelviorectal paraproctitis are distinguished (more on this below). Clinical picture and data of objective research

The onset of the disease is usually acute. In this case, there is an increasing pain in the rectum, perineum or in the pelvis, accompanied by an increase in body temperature and chills. The severity of the symptoms of acute paraproctitis depends on the localization of the inflammatory process, its prevalence, the nature of the pathogen, and the reactivity of the body.

When the abscess is localized in the subcutaneous tissue, there is a painful infiltration in the anus and skin hyperemia, accompanied by an increase in body temperature. Increasing pain, worse when walking and sitting, when coughing, during bowel movements. On palpation, in addition to pain, there is a softening and fluctuation in the center of the infiltrate.

The clinic of ischiorectal abscess begins with general symptoms: feeling unwell, chilling. Then there are dull pains in the pelvis and rectum, aggravated by bowel movements. Local changes - asymmetry of the buttocks, infiltration, flushing of the skin - join in a late stage (on the 5-6th day).

Pelviorectal paraproctitis, in which the abscess is located deep in the pelvis, is the most difficult. In the first days of the disease, general symptoms of inflammation predominate: fever, oz

The rectum is the terminal (end) section of the digestive tract. It is a direct continuation of the large intestine, but it differs from it both in its structure and in its functions.

Rectum structure

The rectum is located in the pelvic cavity. Its length in an adult is approximately 15 cm. It ends with the anus (anus) located on the skin of the perineum.

The rectum consists of three layers: mucous, submucous and muscular. Outside, it is covered with a fairly strong fascia. Between the muscular layer and the fascia itself, there is a thin layer of adipose tissue. In addition to the rectum, this layer surrounds the cervix in women, and in men - the prostate gland and seminal vesicles.

Slightly above the anus, the mucous membrane forms numerous vertical folds - Morgagni's columns. There are folds between the columns, in which small particles of feces, foreign bodies can linger, which in turn can cause the development of an inflammatory process. Constipation, inflammation can lead to the appearance of papilla folds on the surface (elevation of the usual mucous membrane), which are sometimes mistaken for rectal polyps.

Functions of the rectum

In the rectum, feces accumulate and harden before the process of defecation. This evacuation function is largely controlled by the consciousness and will of a person.

Diseases of the rectum

All pathologies of the rectum have a huge impact on the quality and standard of life of any person. Therefore, modern medicine pays great attention to the prevention of diseases and the treatment of the rectum. For the diagnosis of diseases, various instrumental and non-instrumental diagnostic methods are used: physiological, radiological, laboratory research methods. However, the most informative method is colonoscopy, which can detect many, including precancerous diseases and rectal cancer.

The most common diseases of the rectum are:

Proctitis is an inflammatory process in the rectum;
Rectal prolapse - the main cause of this pathology is most often the weakening of the muscles that form the pelvic floor;
Fissures (cracks) - small tears in the rectal mucosa;
Rectal polyps - usually do not cause any discomfort to patients. However, over time, they can degenerate into a malignant tumor;
Rectal cancer is a rather formidable and dangerous disease. Its treatment is prompt and consists in the removal of the rectum (partial or complete with the anus). If a patient with rectal cancer seeks medical help late and it is no longer possible to perform a radical operation, then he is prescribed palliative treatment (radiation, chemotherapy), the purpose of which is to prolong the patient's life and improve its quality. In order to diagnose rectal cancer in a timely manner, you should regularly undergo medical examinations, especially for people suffering from rectal polyps.

The rectum is treated by proctologists. Many diseases are treated conservatively, and only if the therapy is unsuccessful, there are indications for surgical intervention. After removal of the rectum, an unnatural anal opening (colonostomy) is applied or, if the patient's condition allows, reconstructive operations are performed (an artificial rectum is created from the large intestine).

The anus is the final part of the intestine through which the body expels feces (that is, the remains of waste food).

The structure of the human anus

The anal opening is limited by sphincters, which are formed by muscles. These muscle rings are needed to control the opening and closing of the anus. There are two anorectal sphincters in the human body:

Internal, consisting of thickenings of smooth muscles of the rectum and not subject to consciousness. Its length ranges from one and a half to three and a half centimeters.
External, consisting of striated muscles and controlled by consciousness. Its length varies from two and a half to five centimeters.

It ends with an edge, which is a sharp transition of the scaly mucous membrane of the distal part of the anorectal canal into the skin covering of the perineum. The skin around the anus tends to be more pigmented (that is, darker in color) and wrinkled due to the presence of an external sphincter.

In childhood, the anus is located more dorsally than in adults, about twenty millimeters from the tailbone. The diameter of the anus is usually three to six centimeters, and the length of the canal varies from three to five centimeters. In addition to the sphincters, the rectal obturator apparatus includes muscles that lift the anus and the muscles of the pelvic diaphragm.

In the structure of the anus, three sections can be distinguished:

The mucous membrane in this section is equipped with longitudinal folds, between which crypts (anal sinuses) are found, where the openings of the anal glands go out.
The area covered with squamous stratified epithelium.
This section is covered with stratified keratinized squamous epithelium and is equipped with numerous sebaceous and sweat glands, as well as hair.

The area of the anus and rectum has a developed circulatory network, as well as many nerve endings, which allows you to deliberately delay the act of defecation and is often the cause of neurogenic constipation.

Anus topography

Structures that directly interact with the anal canal are the rectal ampulla and the sigmoid colon. The anal canal is located in the perineum. In front, the rectum is adjacent to the seminal vesicles, ampullae of the vas deferens, the bladder and in men. In women, the vagina and uterus are located in front. The canal ends with the anus. Behind, the external sphincter is attached to the coccyx with the help of the anal-coccygeal ligament.

In the region of the perineum, behind and on the sides of the anus, there are paired ischio-rectal fossae, which have the shape of a prism and are filled with adipose tissue, in which nerves and blood vessels pass. In a frontal section, the pits are in the form of triangles. The lateral wall of the fossa is formed by the obturator muscle and the ischial tubercle (inner surface), the medial wall is formed by the external sphincter and muscle that raises the anus. The posterior wall of the fossa is formed by the coccygeal muscle and its posterior bundles, which raises the anus, and the anterior wall is formed by the transverse muscles of the perineum. Fatty tissue, which is located in the cavity of the ischio-rectal fossa, performs the function of an elastic elastic cushion.

The structure of the female anus

In the female body, the rectum is adjacent to the front of the vagina and is separated from the latter by a thin layer of Denovilier-Salishchev. Due to this feature of the structure of the anus and rectum in women, both infectious and tumor agents easily penetrate from one cavity to another, which leads to the formation of rectovaginal fistulas as a result of various injuries or ruptures of the perineum during childbirth.

The structure of the anus in women determines its shape in the form of a flat or slightly protruding formation. This is attributed to the fact that in the process of delivery, the muscles of the perineum relax, and the muscles that raise the anus lose their ability to contract.

Features of the anus in men

The structure of the male anus has some differences. In men (especially muscular ones), the anus looks like a funnel. The anterior wall of the anal canal is adjacent to the bulb and apex of the prostate gland. In addition, the internal sphincter of men is thicker than that of women.

Functions of the anus and rectum

The rectum is responsible for removing waste materials from the body. In addition, fluid is absorbed in it. So, with dehydration and pressing the feces, about four liters of fluid per day are returned to the body. Microelements are absorbed back together with the liquid. The rectal ampulla is a reservoir for feces, the accumulation of which leads to overstretching of the intestinal walls, the formation of a nerve impulse and, as a result, the urge to defecate (defecation).

And now about the functions of the anus. Being in constant tension, its sphincters control the release of feces (defecation) and the release of gases from the intestines (flatulence).

Anus pathology

Tumors.
Haemorrhoids.
Hernia.
Various mucosal defects (cysts, anal fissures, ulcers).
Inflammatory processes (abscesses, paraproctitis, proctitis, fistulas).
Congenital conditions (atresia of the anus).

Sphincter spasm

In accordance with the structure of the anus, the manifestations of pathologies of this part of the intestine are also characteristic. The most common symptom is sphincter spasm (external or internal), which is pain and discomfort in the anus.

The reasons for the appearance of this condition are:

mental problems;
prolonged constipation;
chronic inflammation in the area of the internal or external sphincter;
excess innervation.

Accordingly, the duration is distinguished:

Prolonged spasm, characterized by severe pain, which is not removed by taking ordinary analgesics.
Short-term spasm - sharp short-term acute pain in the anus, radiating to the pelvic joints or tailbone.

Depending on the cause, the spasm can be:

primary (due to neurological problems);
secondary (due to problems in the intestine itself).

The manifestations of this symptom are:

the appearance of pain due to stress;
painful sensations during bowel movements are stopped or with the help of warm water;
the pain is acute, localized in the anus and radiates to the tailbone, pelvis (perineum) or abdomen.

Diagnostics of pathological processes

Computed tomography can detect polyps and other pathological formations.
Biopsy is used to determine malignancy
Anoscopy (rectomanoscopy) is used to assess the condition of the mucous membrane of the anus, as well as to take material for biopsy.
Anorectal manometry. In accordance with the structure of the anus (see photo above), the muscular apparatus (sphincters) of the anus is diagnosed. Most of the time, the anal muscles are tense as much as possible to control bowel movements and flatulence. Up to eighty-five percent of basal anal tone is provided by the internal anal sphincter. With insufficient or absent coordination between the muscles of the pelvic floor and the sphincters of the anus, dyschezia develops, which is manifested by difficult defecation and constipation.
This method allows you to identify hernias, prolapse of the intestine, uterus, hemorrhoids, fistulas, cracks and other pathologies of the anus and rectum.
Ultrasound of the anus. Based on this study, one can assume the presence of neoplasms, determine their location and size, detect, and so on.

Discomfort in the anorectal region

The anatomical structure of the anus is such that the skin in this area is especially sensitive, and pathogenic bacteria can settle in its folds if hygiene is not observed, frequent constipation or diarrhea, resulting in discomfort, irritation, itching, unpleasant odor and pain.

To reduce these manifestations and their prevention, you should:

Wash the anus and the skin around it with water without soap (the latter can dry the skin and, as a result, lead to even more discomfort). Preference should be given to the Cavilon spray or the use of alcohol-free wet wipes (as toilet paper irritates the skin).
The skin around the anus should be dry.
It is necessary to create a barrier to moisture penetration. For example, it is recommended to use the cream "Dimethicone", which creates a protective film on the skin around the anus.
The use of pharmacy powders (for example, talcum powder or cornstarch). They should be applied to previously cleansed and dried skin.
Use of disposable linen or moisture-absorbing pads.
The use of "breathable" linen and clothing made from natural materials with a free cut that does not restrict movement.
In case of fecal incontinence, change your underwear immediately.

Treatment

The appointment of a particular therapy depends on the nature of the disease. First of all, the reasons that caused them are eliminated. In addition, laxatives, antibacterial, analgesic and antispasmodic agents in the form of ointments / suppositories are prescribed, as well as physiotherapy, electrosleep, applications, massage, microclysters. If the conservative treatment is ineffective, surgical operations are performed.

Hemorrhoids are treated with special suppositories and ointments, as well as with surgical methods. Congenital abnormalities (anus atresia) require immediate surgery. Anus tumors are treated with a combination of radiation and chemotherapy, as well as surgical removal of the tumor. Cracks in the anus can be perfectly treated with special baths, diet, healing suppositories and creams, and also surgically. Hernias are eliminated by surgery.

Table of contents of the subject "Colon Anatomy":

Rectum. Rectum topography. Walls, relation to the peritoneum of the rectum.

Rectum, rectum, serves for the accumulation of feces. Starting at the level of the cape, it descends into the small pelvis in front of the sacrum, forming two bends in the anteroposterior direction: one, the upper one, facing the bulge posteriorly, respectively, the concavity of the sacrum - flexura sacralis; the second, lower, facing in the coccyx with a bulge forward, - perineal - flexura perinealis.

Upper rectum, corresponding flexura sacralis, is placed in the pelvic cavity and is called pars pelvina; towards flexura perinealis it expands to form ampoule - ampulla recti, with a diameter of 8 - 16 cm, but can increase with overflow or atony up to 30 - 40 cm.

The ultimate recti part, heading back and down, continues in anal canal, canalis analis, which, passing through the pelvic floor, ends with an anal opening, anus (ring - Greek proktos; hence the name of inflammation - proctitis).
The circumference of this section is more stable, it is 5 - 9 cm. The length of the intestine is 13 - 16 cm, of which 10-13 cm falls on the pelvic section, and 2.5 - 3 cm - on the anal. In relation to the peritoneum in the rectum, three parts are distinguished: the upper one, where it is covered by the peritoneum intraperitoneally, with a short mesentery - mesorectum, middle, located mesoperitoneally, and lower - extraperitoneal.

With the development of rectal surgery, it is now more convenient to use its division into five sections: supra-ampullary (or rectosigmoid), upper ampullary, middle ampullary, lower ampullary and perineal (or canalis analis).

The rectal wall consists of mucous and muscular membranes and located between them muscular plate of the mucous membrane, lamina muscularis mucosae, and submucosa, tela submucosa.

Mucous membrane, tunica mucosa, due to the developed layer of the submucosa, it gathers into numerous longitudinal folds, which are easily smoothed out when the intestinal walls are stretched. V canalis analis longitudinal folds in the amount of 8 - 10 remain constant in the form of the so-called columnae anales... The grooves between them are named anal sinuses, sinus anales, which are especially pronounced in children. The mucus accumulating in the anal sinuses facilitates the passage of feces through the narrow canalis analis.

Anal sinuses, or, as clinicians call them, anal crypts, are the most frequent entry gates for pathogenic microorganisms.

In the thickness of the tissues between the sinuses and the anus is the venous plexus; its painful, bleeding enlargement is called a hemorrhoid.

In addition to the longitudinal folds, in the upper parts of the rectum there are transverse folds of the mucous membrane, plicae transversdles recti, similar to the lunate folds of the sigmoid colon. However, they differ from the latter in a small number (3 - 7) and a helical course, contributing to the forward movement of feces. Submucosa, tela submucosa, highly developed, which predisposes to prolapse of the mucous membrane outward through the anus.

Muscular membrane, tunica muscularis, consists of two layers: inner - circular and outer - longitudinal. The internal one thickens in the upper part of the perineal region up to 5 - 6 mm and forms an internal sphincter here, i.e. sphincter ani internus, 2 - 3 cm high, ending at the junction of the anal canal with the skin. (Immediately under the skin lies a ring of striated arbitrary muscle fibers - m. sphincter ani externus, which is part of the muscles of the perineum).
The longitudinal muscle layer is not grouped in the teniae, as in the colon, but is distributed evenly on the anterior and posterior walls of the intestine. At the bottom, the longitudinal fibers are intertwined with the fibers of the levator the anus, m. levator ani (muscle of the perineum), and partly with the external sphincter.

From the above description, it can be seen that the final segment of the intestine - the rectum - acquires the features of the conductive section of the digestive tube, as well as its initial part - the esophagus. In these both segments of the alimentary canal, the mucous membrane has longitudinal folds, the musculature is located in two continuous layers (inner - circular, narrowing and outer - longitudinal, expanding), and towards the opening that opens outward, myocytes are supplemented with striated arbitrary fibers.
There is a similarity in development: at both ends of the primary intestine, during embryogenesis, the blind ends of the tube break through - the pharyngeal membrane during the formation of the esophagus and the cloacal membrane - during the formation of the rectum. Thus, the similarity in the development and function (carrying out of the contents) of the esophagus and rectum determines the well-known similarity of their structure.

In these features of resemblance to the esophagus, the end part of the rectum differs from the rest of it, which develops from the endoderm and contains smooth muscles.

Rectum topography

Behind the rectum are the sacrum and coccyx, and in front of men it adjoins with its section, devoid of the peritoneum, to the seminal vesicles and vas deferens, as well as to the part of the bladder that is not covered by it, and even lower to the prostate gland.
In women, the rectum in front is bordered by the uterus and the posterior wall of the vagina along its entire length, separated from it by a layer of connective tissue, septum rectovaginale. There are no strong fascial bridges between the intrinsic fascia of the rectum and the anterior surface of the sacrum and coccyx, which facilitates the separation and removal of the intestine along with its fascia, which covers the blood and lymphatic vessels, during operations.

Rectal Anatomy Tutorial Video

Anatomy of the rectum on a cadaver specimen from associate professor T.P. Khairullina understands

The rectum is the final part of the human digestive tract.

The anatomy and physiology of the rectum is different from that of the large intestine. The rectum has an average length of 13-15 cm, the diameter of the intestine ranges from 2.5 to 7.5 cm. The rectum is conventionally divided into two parts: the ampulla of the intestine and the anal canal (anal). The first part of the intestine is located in the pelvic cavity. Behind the ampulla is the sacrum and coccyx. The perineal part of the intestine has the form of a slit located longitudinally, which passes through the thickness of the perineum. In men, in front of the rectum is the prostate gland, seminal vesicles, bladder and ampulla of the vas deferens. In women, the vagina and uterus. In the clinic, it is convenient to use the conditional division of the rectum into the following parts:

nadampular or rectosigmoid;
upper ampullar;
medium ampullar;
lower ampullar part;
crotch part.

Clinical organ anatomy

The rectum has bends: frontal (not always available, changeable), sagittal (permanent). One of the sagittal bends (proximal) corresponds to the concave shape of the sacrum, which is called the sacral bend of the intestine. The second sagittal bend is called the perineal bend, it is projected at the level of the coccyx, in the thickness of the perineum (see photo). The rectum from the proximal side is completely covered by the peritoneum, i.e. located intraperitoneally. The middle part of the intestine is located mesoperitoneally, i.e. covered with peritoneum on three sides. The end or distal part of the intestine is not covered by the peritoneum (located extraperitoneally).

Rectal sphincter anatomy

On the border between the sigmoid colon and the rectum is the sigmoidorectal sphincter, or according to the author O'Berne-Pirogov-Mutier. The basis of the sphincter is made up of smooth muscle fibers located circularly, and an auxiliary element is a fold of the mucous membrane, which occupies the entire circumference of the intestine, located circularly. Three more muscle spasms are located along the intestine.

The third sphincter, or proximal (according to the author Nelaton), has about the same structure as the first sphincter: circular smooth muscle fibers are at the heart, and an additional element is a circular fold of the mucous membrane that occupies the entire circumference of the intestine.
Internal sphincter of the rectum, or involuntary. It is located in the area of the perineal bend of the intestine, ends at the border, where the surface layer of the external sphincter of the anus joins with its subcutaneous layer. The sphincter base consists of thickened smooth muscle bundles that run in three directions (circularly, longitudinally and transversely). The length of the sphincter is from 1.5 to 3.5 cm. The longitudinal fibers of the muscle layer are woven into the distal sphincter and into the external sphincter of the anus, connecting with the skin of the latter. The thickness of this sphincter is greater in men, it gradually increases with age or with certain diseases (accompanied by constipation).
Arbitrary external sphincter. The basis of the sphincter is the striated muscle, which is a continuation of the pubic-rectal muscle. The sphincter itself is located in the pelvic floor area. Its length ranges from 2.5 to 5 cm.The muscular part of the sphincter is represented by three layers of fibers: the subcutaneous part of the circular muscle fibers, the accumulation of superficial muscle fibers (combined and attached to the bones of the tailbone from behind), the layer of deep muscle fibers is connected with the fibers of the pubic-rectal muscle ... The external voluntary sphincter has auxiliary structures: cavernous tissue, arterio-venular formations, connective tissue layer.

All rectal sphincters provide the physiological process of the act of defecation.

Wall structure

The walls of the rectum consist of three layers: serous, muscular and mucous (see photo). The upper part of the intestine is covered with a serous membrane in front and on the sides. In the uppermost part of the intestine, the serosa covers the posterior part of the intestine, passes into the mesentery of the mesorectum. The mucous membrane of the human rectum forms multiple longitudinal folds that are easily straightened. 8 to 10 longitudinal mucous folds of the anal canal are permanent. They are in the form of columns, and between them there are depressions called anal sinuses and ending with semilunar valves. The flaps, in turn, form a slightly protruding zigzag line (called anorectal, dentate or scallop), which is the conditional border between the squamous epithelium of the rectal anal canal and the glandular epithelium of the ampullar part of the intestine. Between the anal opening and the anal sinuses is an annular area called the hemorrhoidal area. The submucosa provides easy movement and stretching of the mucous membrane due to its loose connective tissue structure. The muscle layer is formed by two types of muscle fibers: the outer layer has a longitudinal direction, and the inner one is circular. Circular fibers thicken up to 6 mm in the upper half of the perineal part of the intestine, thereby forming the internal sphincter. Muscle fibers of the longitudinal direction are partially interwoven into the external pulp. They also connect to the muscle that lifts the anus. The external sphincter, up to 2 cm high and up to 8 mm thick, includes arbitrary muscles, covers the perineal region, and the intestine also ends with it. The mucous layer of the rectal wall is covered with epithelium: the anal columns are lined with squamous non-keratinizing epithelium, the sinuses are lined with multilayer epithelium. The epithelium contains intestinal crypts, extending only up to the intestinal pillars. There are no villi in the rectum. A small number of lymphatic follicles are found in the submucosa. Below the sinuses is the border between the skin and the mucous membrane of the anus, which is called the anus-cutaneous line. The skin of the anus has a flat non-keratinizing multilayer pigmented epithelium, papillae are expressed in it, and anal glands are located in the thickness.

Blood supply

Arterial blood approaches the rectum through the unpaired superior rectal and rectal arteries (middle and lower). The superior rectal artery is the last and largest branch of the inferior mesenteric artery. The superior rectal artery provides the main blood supply to the rectum to its anal region. From the branches of the internal iliac artery, the middle rectal arteries depart. Sometimes they are absent or not equally developed. Branches of the lower rectal arteries extend from the internal pudendal arteries. They provide nourishment to the external sphincter and the skin of the anal area. In the layers of the rectal wall, there are venous plexuses, which are called: subfascial, subcutaneous and submucosal. The submucosal, or internal, plexus is connected with the rest and is located in the form of a ring in the submucosa. It consists of dilated venous trunks and cavities. Venous blood flows through the superior rectal vein into the portal vein system, along the middle and lower rectal veins into the inferior vena cava system. There is a large network of anastomoses between these vessels. There are no valves in the superior rectal vein, so veins in the distal rectum often dilate and develop symptoms of venous congestion.

Lymphatic system

Lymphatic vessels and nodes play an important role in the spread of infections and tumor metastases. In the thickness of the rectal mucosa lies a network of lymphatic capillaries, consisting of one layer. In the submucosal layer there are plexuses of lymphatic vessels of three orders. In the circular and longitudinal layers of the rectum, networks of lymphatic capillaries lie. The serous membrane is also rich in lymphatic formations: it has a superficial fine-mesh and deep wide-mesh network of lymphatic capillaries and vessels. The lymphatic vessels of the organ are divided into three types: extramural upper, middle and lower. From the walls of the rectum, the lymph is collected by the upper lymphatic vessels, they run parallel to the branches of the superior rectal artery and flow into the lymph nodes of Gerota. Lymph from the lateral walls of the organ is collected in the middle lymphatic vessels of the rectum. They are directed under the fascia of the levator ani muscle. From them, lymph enters the lymph nodes located on the walls of the pelvis. From the lower rectal lymphatic vessels, lymph goes to the inguinal lymph nodes. The vessels start from the skin of the anus. They are associated with lymphatic vessels from the ampulla of the intestine and from the mucous membrane of the anal canal.

Innervation

Different parts of the intestine have separate branches of innervation. The rectosigmoid and ampullar parts of the rectum are innervated mainly by the parasympathetic and sympathetic nervous systems. The perineal part of the intestine is due to the branches of the spinal nerves. This can explain the low pain sensitivity of the ampullar rectum and the low pain threshold of the anal canal. Sympathetic fibers provide innervation to the internal sphincter, branches of the pudendal nerves - the external sphincter. Branches branch off from the 3rd and 4th sacral nerves, providing innervation to the muscle that lifts the anus.

Functions

The main function of this part of the intestine is to evacuate feces. This function is largely controlled by the consciousness and will of a person. New studies have found that there is a neuroreflex connection between the rectum and the internal organs and systems of the body, carried out through the cerebral cortex and the lower levels of the nervous system. Food begins to evacuate from the stomach within a few minutes after eating. On average, the stomach is emptied of its contents after 2 hours. By this time, the first portions of chyme have reached the bauhinia flap. Up to 4 liters of liquid passes through it per day. The human large intestine provides absorption of about 3.7 liters of the liquid part of the chyme per day. In the form of feces, up to 250-300 grams are evacuated from the body. The mucous membrane of the human rectum ensures the absorption of such substances: sodium chloride, water, glucose, dextrose, alcohol, and many drugs. About 40% of the total mass of feces are undigested food residues, microorganisms, and waste products of the digestive tract. The ampullar part of the intestine acts as a reservoir. In it, feces and gases accumulate, stretch it, irritate the interoceptive apparatus of the intestine. The impulse from the higher parts of the central nervous system reaches the striated muscles of the pelvic floor, smooth muscles of the intestine and striated abdominal fibers. The rectum contracts, the anus is raised, the muscles of the anterior abdominal wall, the pelvic floor diaphragm contract, and the sphincters relax. These are physiological mechanisms that ensure the act of defecation.

Measuring the temperature in the rectum

The rectum is a closed cavity, so the temperature in it is relatively constant and stable. Therefore, the results of thermometry in the rectum are the most reliable. The temperature of the rectum is almost equal to the temperature of the human organs. This method of thermometry is used in a certain category of patients:

patients with severe exhaustion and weakness;
children under the age of 4-5 years;
patients with thermoneuroses.

Contraindications are rectal diseases (hemorrhoids, proctitis), stool retention, when the ampullar part of the intestine is filled with feces, diarrhea. Before you start measuring the temperature, you need to lubricate the end of the thermometer with petroleum jelly. An adult patient can lie on his side, it is more convenient for children to lie on their stomachs. The thermometer is introduced no more than 2-3 cm. An adult patient can do it himself. During the measurement, the patient continues to lie, the thermometer is held by the fingers of the hand, which lies on the buttocks. A sharp introduction of the thermometer, its rigid fixation or movement of the patient during measurement is excluded. The measurement time will be 1-2 minutes if you are using a mercury thermometer.

The normal temperature in the rectum is 37.3 - 37.7 degrees.

After measuring, place the thermometer in a disinfectant solution, store in a separate place. The following symptoms may indicate diseases of the rectum.

Constipation. To determine the cause of constipation, you should consult a specialist and undergo the necessary research. Constipation can be a sign of serious diseases: intestinal obstruction, neoplastic diseases, intestinal diverticulosis.
Symptoms indicating the presence of a chronic anal fissure: spotting with scarlet blood after the act of defecation, pain before and after defecation. The proctologist will detect this disease during a routine visual examination.
Sharp intense pain in the rectal area, disturbance of general well-being and fever with signs of intoxication are indications for calling an ambulance specialist. The listed symptoms may indicate an inflammatory process of the subcutaneous fatty tissue - paraproctitis.
The reason for contacting a specialist is the nonspecific symptoms characteristic of many diseases of the rectum (cancer, polyps, hemorrhoids): a sharp weight loss, there is an admixture of blood, mucus in the feces, the patient is disturbed by severe pain before and after the act of defecation.