Rectum. Topography of the rectum. Walls, relation to the peritoneum of the rectum. What is the structure of the rectum in women and men? Folds of the rectum

The rectum is a “straight” organ in lower mammals - hence its Latin name. However, in humans, it curves 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 ensured by nerves located in the danger zone, which can be damaged during surgical interventions in the depths 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. Particularly great difficulties arise when it is necessary to restore intestinal continuity, since the operation takes place in a limited 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 there is an ampulla and a small area above it - the supramullary part. The perineal section of the rectum is also called the anal canal.

The supramullary part of the intestine is covered by peritoneum on all sides. Next, the intestine begins to lose peritoneal cover, first from the back, being covered with 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 mucous membrane of the rectum has longitudinal folds, which are often called Morganian columns. Between them are the anal (Morgani) sinuses, bounded below by the semilunar anal valves. Transverse folds of the mucosa, which do not disappear when the rectum is filled, are located in its different parts. One of them corresponds to position n. sphincter tertius and is located on the border between the ampullary and supramullary parts of the intestine. The intestinal mucosa forms folds: closer to the anus - longitudinal, and higher - transverse. In the ampullary part there is one fold on the right wall, two on the left. At the border of the ampullary and anal parts of the rectum, corresponding to the position of the internal sphincter, there is a well-defined fold, especially on the posterior wall of the intestine - valvula Houstoni. When the intestine fills, these folds can straighten and increase its volume.

At a distance of 3–4 cm from the anus, annular muscle fibers, thickening, form the internal sphincter, and at a distance of approximately 10 cm from the anus there is another thickening of the circular muscle fibers, known as the Hepner muscle (m.sphincter tertius). The external sphincter 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 ones – a. rectales media (branch of a. iliaca interna) and a. rectalis inferior (branch of 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. There are external and internal hemorrhoidal plexuses. The external plexus is located under the skin of the anus, in the circumference and on the surface of the external sphincter 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 rectal fascia. 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 penetrating between the circular bundles. 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 vein and belongs to the portal vein system, and the middle and lower ones belong to the inferior vena cava system: the middle ones flow into the internal iliac veins, and the lower ones into the internal pudendal veins (Fig. 195).

Rice. 193. Anatomy of the rectum. 1 – middle transverse fold (valvula Houstoni); 2 – upper transverse fold (valvula Houstoni); 3 – muscle that lifts 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 pudendal artery; 7 – inferior rectal artery; 8 – internal iliac artery; 9 – obturator artery; 10 – median sacral artery; 11 – superior cystic artery; 12 – inferior cystic artery; 13 – middle rectal artery; 14 – superior rectal artery

Rice. 195. Veins of the rectum. 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 – cystic (upper) and uterine veins; 11 – middle rectal vein; 12 – internal pudendal vein; 13 – portocaval anastomoses; 14 – inferior cystic veins; 15 – internal pudendal vein; 16 – inferior 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 vessels. Lymphatic drainage 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.

For successful surgical interventions in the pelvis, knowledge of the detailed anatomy of the mesorectum and its contents in adults plays a critical role.

Mesorectum (a set 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 is derived from the dorsal mesentery, a general visceral mesentery surrounding the rectum, and is covered by a layer of visceral fascia, providing a relatively bloodless layer, the so-called “holy plane” mentioned by Heald. The goal of surgery is to gain access while remaining within this fascial layer. Posteriorly, this layer passes between the visceral fascia surrounding the mesorectum and the parietal presacral fascia (Fig. 196). The last layer is usually referred to as Waldeyer's fascia. Inferiorly, at the S4 level, these fascial layers (mesorectal and Waldeyer) unite into the rectosacral ligament, which must be divided when mobilizing the rectum.

A more accurate understanding of the rectum, mesorectum, innervation and vascularization of them and 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. Mesorectum. 1 – mesorectum; 2 – The lymph nodes; 3 – visceral fascia; 4 – lumen of the rectum. T – tumor growing into the mesorectum

What is Hemorrhoids

Hemorrhoids are a pathological enlargement of the cavernous vascular plexuses 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 share of hemorrhoids in the structure of coloproctological diseases is 35–40%. Behind medical assistance From 10 to 60% of patients with this disease are treated. Many patients self-medicate for a long time and seek help only when various complications develop 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. Even 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, with the fact that people who drink a lot of strong drinks and spicy foods are more susceptible to this disease.

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

In the 30s of the 20th century, Milligan and Morgan proposed an operation - hemorrhoidectomy - to treat hemorrhoids. Various modifications of it are still used today.

Etiology and pathogenesis

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

Rice. 197. Localization of hemorrhoids. 1 – on the posterolateral 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

Cavernous plexuses are 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, and the cavernous cavities (sinuses) are unclear. With age, the size of the sinuses and individual cavernous plexuses increases and this is the anatomical substrate of the future main internal hemorrhoids. The hemorrhoidal plexuses are an important anatomical formation that plays a decisive role in the so-called “thin” anal holding of stool. Due to their elastic consistency, there is a delay in the venous outflow of blood when the m is tense. sphincter ani internus. All this makes it possible to retain solid components of feces, air and liquid in the rectal ampulla. Relaxation of the sphincter during defecation leads to the outflow of blood from the hemorrhoidal plexuses and emptying of the rectal ampulla. It should be noted that such a physiological mechanism occurs during the formation of normal feces. Too hard stool inhibits the urge to defecate, while the hemorrhoidal plexuses become overfilled with blood for much longer. Subsequently, their pathological expansion and further transformation into hemorrhoids occurs. On the other hand, and loose stool too stimulating frequent bowel movements rectum, which occurs, as a rule, against the background of a not completely relaxed sphincter and still crowded hemorrhoidal plexuses. Their constant traumatization occurs, which ultimately leads to secondary changes, i.e., 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 cavernous bodies. Factors such as pregnancy and childbirth, obesity, excessive alcohol and coffee consumption, chronic diarrhea, sedentary, sedentary lifestyle life, straining during bowel movements, smoking, heavy lifting, and prolonged coughing lead to increased intra-abdominal pressure and stagnation of blood in the pelvis. Hemorrhoids increase in size. Development of dystrophic processes in general longitudinal muscle the submucosal layer of the rectum and the Parkes ligament, which hold the cavernous bodies in the anal canal, leads to a gradual but irreversible displacement of the 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) spicy;

2) chronic.

Highlight 4 stages of chronic hemorrhoids:

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

Stage II– hemorrhoids fall out when straining and are reduced on their own.

Stage III– hemorrhoids fall out and can only be adjusted manually. Moreover, at first the nodes fall out only during defecation, and then with an increase in intra-abdominal pressure.

IV stage– hemorrhoids fall out even at rest, are not reduced or fall out again immediately after reduction.

In addition, there are three degree of severity acute hemorrhoids:

I degree– external hemorrhoids are small in size, have a tight-elastic consistency, are painful on palpation, the perianal skin is slightly hyperemic, patients experience a burning sensation and itching, which intensifies with defecation.

II degree– characterized by pronounced swelling of most of the periphery anal area 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 the inflammatory infiltrate, palpation is sharply painful, in the area of the anus purple or bluish-purple internal hemorrhoids covered with fibrin deposits are visible. If left untreated, node necrosis may occur. Clinical picture and objective research data

Complaints. The patient develops complaints, as a rule, when complications of hemorrhoids occur - thrombosis of hemorrhoids or bleeding from these nodes. In this case, patients are concerned about the prolapse or protrusion of a dense, painful node from the anus (with thrombosis), the presence of scarlet blood in the stool (with bleeding) - from small drops and streaks to heavy bleeding. These complaints are usually 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. These symptoms are especially aggravated after eating a lot of spicy food, which is due to stagnation of blood in the pelvic area.

In external hemorrhoids, the hemorrhoidal plexuses are located distal to the dentate line, in the anal canal, lined with anoderm. It, together with the adjacent skin, 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. In internal hemorrhoids, the nodes are located proximal to the dentate line of the anal canal, under the mucous membrane, which is innervated 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 complaints. One of the first symptoms is anal itching. Bleeding usually appears later. The resulting bleeding is often persistent, prolonged and intense, sometimes leading to severe anemia. Subsequently, patients begin to notice protrusion and prolapse of the nodes, often with a tendency to become inflamed or pinched.

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 examination of the anal area. In this case, you can see enlarged, collapsed or compacted and inflamed hemorrhoids at 3, 7 and 11 o’clock (Fig. 199). In some patients, the nodes are not clearly grouped in the indicated places, which indicates the scattered nature of the cavernous bodies of the rectum. The internal nodes may resemble a mulberry and bleed easily on contact. When the patient strains, the nodes may protrude outward. With a digital examination, hemorrhoids can be identified, which during an exacerbation become dense and sharply painful. Therefore, in case of obvious thrombosis of hemorrhoids, digital examination should be carried out with extreme caution or even refrain from it. With long-standing 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 upper parts of the rectum and exclude other diseases, in particular a tumor process.

To do this, you should perform irrigoscopy and/or fibrocolonoscopy. Differential diagnosis

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

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

Moreover, as already indicated, the reason varicose veins rectal veins may have portal hypertension.

Complications

1. Bleeding. Occurs when the mucous membrane over the hemorrhoidal node becomes thinner, while blood flows out from erosions or diffusely. It is fresh and liquid. Blood appears on toilet paper or drips after defecation from the anus. Patients note such bleeding periodically; it is more often observed with constipation. In case of rectal cancer or ulcerative colitis, blood in the stool is observed with any stool (not necessarily dense), with tenesmus and is mixed with stool, and with hemorrhoids, blood covers the stool. Repeated, even small, hemorrhoidal bleeding, as already noted, can lead to anemia.

2. Inflammation. When inflamed, internal hemorrhoids are red, enlarged, painful, bleeding from superficial erosions. Reflex spasms of the anus occur, and digital examination can be painful.

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

4. Prolapse of hemorrhoids. If 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 (prolapsed hemorrhoids).

Treatment of hemorrhoids can be conservative or surgical.

Diet. If you have hemorrhoids, you need to eat regularly, at the same time, eat more vegetable fiber against the background of increased water consumption (1.5–2 liters per day). You should limit products made from white refined flour and whole milk, while fermented milk products can and should be consumed daily, especially those enriched with bifidobacteria and lactobacilli. Drinking mineral waters enhances intestinal motility. Highly and moderately mineralized waters are recommended, as well as waters containing magnesium ions and sulfates, such as “Essentuki”, “Moskovskaya”. It is necessary to exclude alcoholic drinks, as well as hot, spicy, fried, smoked foods, since the consumption of these products leads to an increase in blood flow in the perianal area and blood stagnation in the pelvic area.

Problems that must be solved drug therapy, the following: cupping pain syndrome, thrombosis of the hemorrhoid, elimination of the inflammatory process and prevention of re-exacerbation of hemorrhoids. When choosing local treatment 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 should be assessed posthemorrhagic anemia. It should be noted that the prevention of exacerbation, first of all, consists in normalizing the activity of the digestive tract, treating constipation, which occurs in more than 75% of patients with hemorrhoids. Increased intake of fiber and fluid leads to softening of stool, 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 bread, brown rice and wholemeal pasta, fruits, vegetables and salads (at least three servings of vegetables and fruits daily), and legumes (lentils, beans, peas, etc.). If diet therapy is ineffective, you should resort to laxatives (for example, Fibodel, Regulan, Normacol, Normacol-plus, methyl cellulose).

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

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

Combined drugs containing analgesic, thrombolytic and anti-inflammatory components are indicated for thrombosis of hemorrhoids complicated by their inflammation. This group of drugs includes proctosedyl and hepatothrombin G, produced in the form of ointment, gel bases and suppositories. Pharmacokinetics last drug is that heparin and allantoin, by binding plasma coagulation factors and having an inhibitory effect on hemostasis, cause a thrombolytic effect, and panthenol stimulates metabolic processes, granulation and epithelialization of tissues. Polidocanol, which is part of it, provides an analgesic effect. To relieve inflammation, in addition to local treatment, nonsteroidal anti-inflammatory drugs are used that have a combined effect, including analgesic (ketoprofen, diclofenac, indomethacin, etc.).

Basis general treatment is the use of phlebotropic medicines, affecting the increase in the tone of the veins, improvement of microcirculation in the cavernous bodies and normalization of 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, Endotelon, etc.

If conservative treatment is ineffective, especially in the later stages of the disease, combined 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 interventions for hemorrhoids: injection sclerotherapy, infrared coagulation, latex ring ligation, cryotherapy, diathermic coagulation, bipolar coagulation.

At stage I of hemorrhoids, sclerotherapy has proven itself 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 sufficient, the procedure is repeated 2-3 times within two weeks. For sclerotherapy according to Blanchard (Fig. 200), a sclerosant solution is injected directly into the area of the vascular pedicle of the hemorrhoid in typical places (3, 7, 11 hours).

Rice. 200. Introduction of sclerosant into the area of the vascular pedicle of the hemorrhoid (according to Blanchard)

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

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

Surgical treatment carried out in patients with stages III and IV of the disease.

Rice. 201. Ligation of internal hemorrhoids. A – capture of the hemorrhoid with a clamp; B – dropping 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 currently is the Milligan-Morgan hemorrhoidectomy, which gives good results. The essence of the operation is to excise hemorrhoids from the outside inward with ligation of the vascular pedicle of the node, cutting off the node. As a rule, three external and corresponding three internal nodes are excised at 3, 7, 11 o'clock, with the obligatory leaving of bridges of the mucous membrane between them in order to avoid narrowing of the anal canal. Three modifications of the operation are used:

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

Open - leaving an unsutured wound (if there is a risk of narrowing of the anal canal and complications such as anal fissure, paraproctitis) (Fig. 203);

Under mucosal hemorrhoidectomy (from under the mucous layer with a high-frequency coagulator sharp way The node is removed, leaving the stump of the node in the submucosal layer under the sutured mucosa. Transanal mucosal resection using the Longo method is an alternative to the classical surgical intervention for excision of hemorrhoids (Fig. 204). In 1993, Italian Antonio Longo developed a fundamental new approach for surgical intervention for hemorrhoids. The essence of the operation is to perform a circular resection and suturing the prolapsed mucosa with hemorrhoids. During the Longo operation, only the part of the rectal mucosa that 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 anal canal wound with a continuous suture

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

The mucosal defect is stitched using a circular stapler using the “end to end” type. As a result, hemorrhoids are not removed, but are pulled up and sharply reduced in volume due to a decrease in blood flow into the cavernous bodies. Due to the excision of the circular strip of the mucosa, conditions are created under which the blood supply to the nodes decreases, which leads to their gradual desolation and zobliteration.

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

The prognosis for hemorrhoids is usually favorable. Application conservative therapy, minimally invasive methods, either alone or in combination with each other or with surgical methods, allow one to achieve good results in 85–90% of patients.

Acute paraproctitis

Acute paraproctitis is an acute purulent inflammation of the peri-rectal tissue. In this case, the infection penetrates into the tissues of the peri-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 diseases of the rectum). 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 perirectal tissue. The causative agents of the disease are Escherichia coli, staphylococcus, gram-negative and gram-positive bacilli. Most often, polymicrobial flora is detected. Inflammation caused by anaerobes is accompanied by particularly severe manifestations of the disease - gaseous cellulitis 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 penetrate into the perirectal tissue from the anal glands, which 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 intersphincteric space, which breaks into the perianal or pararectal space. The transition of the process from the inflamed gland to the perirectal tissue is also possible through the lymphogenous route. In the development of paraproctitis, trauma to the rectal mucosa by foreign bodies contained in feces, hemorrhoids, anal fissures, nonspecific ulcerative colitis, Crohn's disease. Paraproctitis can be secondary. In this case, the inflammatory process moves to the perirectal tissue with prostate gland, urethra, female genital organs. Rectal injuries are a rare cause of post-traumatic paraproctitis. The spread of pus through the perirectal cellular spaces can go in different directions, which leads to the formation various forms paraproctitis.

Classification

According to etiology, paraproctitis is divided into banal, specific And post-traumatic.

According to the activity of the inflammatory process - on acute, infiltrative And chronic (rectal fistulas).

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

You can select 4 levels of difficulty acute paraproctitis.

Paraproctitis of the first degree of complexity includes subcutaneous, submucosal, ischiorectal forms that have an intrasphincteric connection with the lumen of the rectum, intermuscular (intersphincteric) paraproctitis.

To the II degree of complexity - ischial, retrorectal forms of paraproctitis with transsphincteric communication through the superficial portion of the anal sphincter (less than 1/2 portion, i.e. less than 1.5 cm).

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

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

Rice. 205. Options for localizing ulcers: 1 – subcutaneous; 2 – intermuscular;

3 – ischiorectal; 4 – pelviorectal.

There are subcutaneous, ischeorectal and pelviorectal paraproctitis (more about this below). Clinical picture and objective examination data

The onset of the disease is usually acute. In this case, increasing pain appears in the rectum, perineum or 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 subcutaneous tissue there is a painful infiltrate in the anus and skin hyperemia, accompanied by an increase in body temperature. Increasing pain, intensifying when walking and sitting, when coughing, when defecating. On palpation, in addition to pain, there is softening and fluctuation in the center of the infiltrate.

The clinical picture of ischiorectal abscess begins with general symptoms: feeling unwell, chilling. Then they appear dull pain in the pelvis and rectum, aggravated by defecation. Local changes - asymmetry of the buttocks, infiltration, skin hyperemia - join in late stage(on the 5th-6th day).

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

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

Structure of the rectum

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, submucosal and muscular. On the outside it is covered with a fairly strong fascia. Between the muscle sheath and the fascia itself there is a thin layer of fatty tissue. In addition to the rectum, this layer surrounds the cervix in women, and the prostate gland and seminal vesicles in men.

Somewhat above the anus, the mucous membrane forms numerous vertical folds - Morgagni columns. There are folds between the columns in which small particles of feces and foreign bodies can be retained, which in turn can cause the development of an inflammatory process. Constipation and inflammation can lead to the appearance of papillary folds on the surface (an elevation of the normal mucous membrane), which are sometimes mistaken for rectal polyps.

Functions of the rectum

In the rectum, feces accumulate and harden before 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. That's why modern medicine pays great attention to the prevention of diseases and treatment of the rectum. To diagnose diseases, various instrumental and non-instrumental diagnostic methods are used: physiological, radiological, laboratory methods research. However, the most informative method is a colonoscopy, which allows you to identify 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 a weakening of the muscles that form the pelvic floor;
Fissures (cracks) are small tears in the mucous membrane of the rectum;
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 surgical and consists of removing the rectum (partial or complete along with the anus). If a patient with rectal cancer seeks medical help late and radical surgery is no longer possible, 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 undergo regular medical examinations, especially for people suffering from rectal polyps.

Proctologists treat the rectum. Many diseases are treated conservatively, and only if the therapy is unsuccessful, indications for surgery arise. After removal of the rectum, an unnatural anal opening (colonostomy) is created or, if the patient’s condition allows, reconstructive surgery is performed (an artificial rectum is created from a section of 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 anus is limited by sphincters, which are formed by muscles. Such muscle rings are necessary to control the opening and closing of the anus. There are two anorectal sphincters in the human body:

Internal, consisting of thickenings of the 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 from the scaly mucous lining of the distal anorectal canal to the skin covering of the perineum. The skin in the anal area tends to be more pigmented (that is, darker in color) and wrinkled due to the presence of the external sphincter.

In childhood, the anus is located more dorsally than in adults, approximately twenty millimeters from the coccyx. 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 elevate the anus and the muscles of the pelvic diaphragm.

The structure of the anus can be divided into three sections:

The mucous membrane in this section is equipped with longitudinal folds, between which crypts (anal sinuses) are found, into which the openings of the anal glands emerge.
Area covered by flat stratified epithelium.
This section is covered with stratified keratinized squamous epithelium and is supplied 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 makes it possible to consciously delay the act of defecation and is often the cause of neurogenic constipation.

Topography of the anus

The 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, ampoules of the vas deferens, and the bladder in men. In women, the vagina and uterus are located in front. The canal ends with the anus. Posteriorly, the external sphincter is attached to the coccyx using the anal-coccygeal ligament.

In the perineal area behind and on the sides of the anus there are paired ischiorectal fossae, shaped like a prism and filled with fatty tissue, in which nerves and blood vessels pass. In a frontal section, the fossae have the shape of triangles. The lateral wall of the fossa is formed by the obturator muscle and the ischial tuberosity (inner surface), the medial wall is formed by the external sphincter and the muscle that elevates the anus. The posterior wall of the fossa is formed by the coccygeus muscle and its posterior bundles, which elevates 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 ischiorectal fossa, functions as an elastic elastic cushion.

The structure of the female anus

IN female body The rectum is adjacent to the vagina in front and is separated from the latter by a thin layer of Denovillier-Salischev. Due to this structural feature 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 as a flat or slightly protruding formation. This is due to the fact that during the process of delivery the muscles of the perineum relax, and the muscles that lift 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 men), 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 substances from the body. In addition, liquid is absorbed in it. Thus, when feces are dehydrated and compressed, about four liters of fluid per day are returned to the body. Microelements are reabsorbed along 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 consequence, the urge to defecate.

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).

Pathologies of the anus

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

Sphincter spasm

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

The reasons for this condition are:

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

Accordingly, the durations are distinguished:

Prolonged spasm, characterized by severe pain, which cannot be relieved by taking ordinary analgesics.
Transient spasm - sharp short-term sharp pains in the anus, radiating to the pelvic joints or tailbone.

Depending on the cause, the spasm may be:

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

Manifestations of this symptom are:

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

Diagnosis of pathological processes

Computed tomography can detect polyps and other pathological formations.
A biopsy is used to determine malignancy
Anoscopy (rectomanoscopy) is used to assess the condition of the anal mucosa, as well as to take material for a 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 kept at maximum tension to control bowel movements and flatulence. Up to eighty-five percent of basal anal tone is carried out by the internal anal sphincter. With insufficient or absent coordination between muscles pelvic floor and the sphincters of the anus develop dyschezia, which is manifested by difficult bowel movements and constipation.
This method allows you to identify hernias, intestinal prolapse, uterine prolapse, hemorrhoids, fistulas, fissures and other pathologies of the anus and rectum.
Ultrasound of the anus. Based this study one can assume the presence of neoplasms, determine their location and size, detect them, and so on.

Discomfort in the anorectal area

The anatomical structure of the anus is such that the skin in this area is especially sensitive, and in its folds, due to poor hygiene, frequent constipation or diarrhea, pathogenic bacteria can settle, which can result in discomfort, irritation, itching, bad smell and pain.

To reduce these manifestations and prevent them, you should:

Wash the anus and the skin around it with water without soap (the latter can dry out the skin and, as a result, lead to even greater discomfort). It is necessary to give preference to Cavilon spray or the use of alcohol-free wet wipes (since toilet paper irritates the skin).
The skin in the anal area should be dry.
It is necessary to create a barrier to moisture penetration. For example, it is recommended to use Dimethicone cream, which creates a protective film on the skin around the anus.
Using pharmaceutical powders (for example, talc or cornstarch). They should be applied to previously cleansed and dried skin.
Use of disposable underwear or moisture-absorbing pads.
Using “breathable” underwear and clothes made from natural materials with a loose fit that does not restrict movement.
In case of fecal incontinence, underwear should be replaced immediately.

Treatment

The prescription of a particular therapy depends on the nature of the disease. First of all, they eliminate the reasons that caused them. In addition, laxatives, antibacterial, painkillers and antispasmodics in the form of ointments/suppositories are prescribed, as well as physiotherapy, electrosleep, applications, massage, microenemas. If conservative treatment is ineffective, surgical operations are performed.

Treatment of hemorrhoids is carried out using special suppositories and ointments, as well as surgical methods. Congenital pathologies(anal atresia) require immediate surgery. Anal tumors are treated with a combination of radiation and chemotherapy, as well as surgical removal of the tumor. Cracks in the anal area can be easily treated with the use of special baths, diet, healing suppositories and creams, as well as surgically. Hernias are eliminated surgically.

Table of contents of the topic "Anatomy of the large intestine":

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

Rectum, rectum, serves for the accumulation of feces. Starting at the level of the promontory, it descends into the small pelvis in front of the sacrum, forming two bends in the anteroposterior direction: one, upper, convexly facing backward, corresponding to the concavity of the sacrum - flexura sacralis; second, lower, facing in the area of the coccyx with the convexity 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 final part of the recti, going backwards and downwards, continues in anal canal, canalis analis, which, having passed through the pelvic floor, ends with the anus, anus (ring - Greek proktos; hence the name of inflammation - proctitis).
The circumference of this section is more stable, 5 - 9 cm. The length of the intestine is 13 - 16 cm, of which 10-13 cm is in the pelvic section, and 2.5 - 3 cm in the anal section. In relation to the peritoneum, three parts are distinguished in the rectum: the upper one, where it is covered with 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 divide it into five sections: supramullary (or rectosigmoid), superior ampullary, mid-ampullary, inferior ampullary and perineal (or canalis analis).

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

The anal sinuses, or anal crypts as clinicians call them, are the most common portal of entry for pathogenic microorganisms.

In the thickness of the tissue between the sinuses and the anus there is a venous plexus; its painful, heavily bleeding expansion is called hemorrhoids.

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

Muscular membrane, tunica muscularis, consists of two layers: internal - circular and external - longitudinal. The internal one thickens in the upper part of the perineal section to 5 - 6 mm and forms here the internal sphincter, 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 voluntary muscle fibers - m. sphincter ani externus, part of the muscles of the perineum).
The longitudinal muscle layer is not grouped in teniae, as in colon, but is distributed evenly on the anterior and posterior walls of the intestine. Below, the longitudinal fibers intertwine with the fibers of the levator ani muscle, m. levator ani (perineal muscle), and partly with the external sphincter.

From the above description it is clear that the final segment of the intestine - the rectum - acquires the features of the conductive section of the digestive tube, just like its initial part - the esophagus. In both of these sections of the digestive canal, the mucous membrane has longitudinal folds, the muscles are located in two continuous layers (inner - circular, narrowing and outer - longitudinal, expanding), and towards the hole that opens outward, the myocytes are supplemented with striated arbitrary fibers.
There are also similarities in development: at both ends of the primary intestine, during embryogenesis, a breakthrough occurs at the blind ends of the tube - the pharyngeal membrane during the formation of the esophagus and the cloacal membrane during the formation of the rectum. Thus, the similarity of development and function (carrying out the contents) of the esophagus and rectum also determines the known similarity of their structure.

By these similarities with the esophagus, the final part of the rectum differs from the rest of it, which develops from the endoderm and contains smooth muscle.

Topography of the rectum

Posterior to the rectum are the sacrum and coccyx, and in front in men it adjoins its section, devoid of peritoneum, to the seminal vesicles and vas deferens, as well as to the area of the bladder that lies between them and is not covered by it, and even lower to the prostate gland.
In women, the rectum borders the uterus in front and back wall vagina along its entire length, separated from it by a layer connective tissue, septum rectovaginale. There are no strong fascial bridges between the fascia of the rectum and the anterior surface of the sacrum and coccyx, which makes it easier during operations to separate and remove the intestine along with its fascia, covering the blood and lymphatic vessels.

Educational video on rectal anatomy

Anatomy of the rectum on a cadaveric 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 differs 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 (anus). 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 there is a 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:

supramullary or rectosigmoid;
superior ampullary;
mid-ampullary;
inferior ampullary part;
crotch part.

Clinical anatomy of the organ

The rectum has bends: frontal (not always present, changeable), sagittal (constant). 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 curve is called perineal and is projected at the level of the coccyx, in the thickness of the perineum (see photo). The rectum on 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 terminal or distal part of the intestine is not covered by the peritoneum (located extraperitoneally).

Anatomy of the rectal sphincters

On the border between the sigmoid colon and the rectum there is the sigmorectal sphincter, or according to the author O'Berne-Pirogov-Muthier. The basis of the sphincter is made up of smooth muscle fibers, located circularly, and the auxiliary element is a fold of the mucous membrane, occupying the entire circumference of the intestine, located circularly. Along the intestine there are three more muscle sphincter.

The third sphincter or proximal (according to the author Nelaton), has approximately the same structure as the first sphincter: it is based on circular smooth muscle fibers, and an additional element is a circular fold of the mucosa, which occupies the entire circumference of the intestine.
Internal sphincter of the rectum, or involuntary. It is located in the area of the perineal flexure of the intestine, ending at the border where the superficial layer of the external anal sphincter connects with its subcutaneous layer. The base of the sphincter 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).
Voluntary external sphincter. The basis of the sphincter is the striated muscle, which is a continuation of the puborectalis muscle. The sphincter itself is located in the pelvic floor. 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, a cluster of superficial muscle fibers (united and attached to the bones of the coccyx at the back), a layer of deep muscle fibers associated with the fibers of the puborectalis muscle . The external voluntary sphincter has auxiliary structures: cavernous tissue, arteriolo-venular formations, connective tissue layer.

All rectal sphincters provide the physiological process of defecation.

Wall structure

The walls of the rectum consist of three layers: serous, muscular and mucous (see photo). Top part the intestines are 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 and passes into the mesorectum. The mucous membrane of the human rectum forms multiple longitudinal folds that are easily straightened. From 8 to 10 longitudinal mucous folds of the anal canal are permanent. They have the shape of columns, and between them there are depressions called the anal sinuses and ending with semilunar valves. The valves, in turn, form a slightly protruding zigzag line (called anorectal, dentate or scalloped), which is the conventional boundary between the squamous epithelium of the rectal anal canal and glandular epithelium ampullary part of the intestine. Between the anus and the anal sinuses there is a ring-shaped zone called hemorrhoidal. 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, the inner layer has a circular direction. The circular fibers thicken to 6 mm in the upper half of the perineal part of the intestine, thereby forming the internal sphincter. Muscle fibers in the longitudinal direction are partially woven into the external sphincter. They also connect to the levator ani muscle. The external sphincter, up to 2 cm high and up to 8 mm thick, contains voluntary muscles, covers the perineal section, and also ends with the intestine. The mucous layer of the rectal wall is covered with epithelium: the anal columns are lined with flat non-keratinizing epithelium, the sinuses are lined with stratified epithelium. The epithelium contains intestinal crypts, extending only to the intestinal columns. There are no villi in the rectum. A small number of lymphatic follicles are found in the submucosa. Below the intestinal sinuses there is a boundary between the skin and the mucous membrane of the anus, which is called the anal-cutaneous line. The skin of the anus has a flat, non-keratinizing stratified pigmented epithelium, papillae are pronounced in it, and the anal glands are located in its 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. The middle rectal arteries depart from the branches of the internal iliac artery. Sometimes they are absent or not equally developed. Branches of the inferior rectal arteries arise from the internal pudendal arteries. They provide nutrition to the external sphincter and the skin of the anal area. In the layers of the rectal wall there are venous plexuses, called subfascial, subcutaneous and submucosal. The submucosal, or internal, plexus is connected to the others and is located in the form of a ring in the submucosa. It consists of dilated venous trunks and cavities. Deoxygenated blood flows through the superior rectal vein into the portal vein system, through the middle and lower rectal veins into the inferior vena cava system. Between these vessels there is a large network of anastomoses. The superior rectal vein lacks valves, so the veins in the distal rectum often dilate and develop symptoms of venous stasis.

Lymphatic system

Lymphatic vessels and nodes play a large role in the spread of infections and tumor metastases. In the thickness of the mucous membrane of the rectum 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 there are networks of lymphatic capillaries. The serous membrane is also rich in lymphatic formations: it has a superficial finely looped and deep broadly looped 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, lymph is collected by the upper lymphatic vessels, they run parallel to the branches of the superior rectal artery and empty into the lymph nodes of Gerota. Lymph from the side 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 flows into 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 begin from the skin of the anus. Lymphatic vessels from the ampulla of the intestine and from the mucous membrane of the anal canal are connected to them.

Innervation

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

Functions

The main function of this section of the intestine is to evacuate feces. This function is largely controlled by the consciousness and will of a person. New research has found that between the rectum and internal organs and the body systems there is a neuroreflex connection carried out through the cerebral cortex and the lower levels of the nervous system. Food begins to be evacuated from the stomach just a few minutes after eating. On average, the stomach is empty of its contents after 2 hours. By this time, the first portions of chyme reach the bauhinium valve. Up to 4 liters of liquid pass through it per day. The human colon absorbs about 3.7 liters of the liquid part of chyme per day. Up to 250-300 grams are evacuated from the body in the form of feces. The human rectal mucosa ensures the absorption of the following substances: sodium chloride, water, glucose, dextrose, alcohol, and many medications. About 40% of the total mass of feces consists of undigested food debris, microorganisms, and waste products of the digestive tract. The ampullary part of the intestine acts as a reservoir. Feces and gases accumulate in it, stretch it, and 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 fibers abdominals. The rectum contracts, the anus rises, the muscles of the anterior abdominal wall, the pelvic floor diaphragm contract, and the sphincters relax. This physiological mechanisms, ensuring the act of defecation.

Measuring rectal temperature

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 human organs. This method of thermometry is used in a certain category of patients:

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

Contraindications include diseases of the rectum (hemorrhoids, proctitis), stool retention when the ampullary part of the intestine is filled with feces, and diarrhea. Before you start measuring 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 to place children on their stomach. The thermometer is inserted no more than 2-3 cm. An adult patient can do this himself. During the measurement, the patient continues to lie down, the thermometer is held with the fingers of the hand, which lies on the buttocks. Avoid abrupt insertion of the thermometer, its rigid fixation, or movement of the patient during measurement. The measurement time will be 1-2 minutes if you use a mercury thermometer.

Normal temperature in the rectum is 37.3 - 37.7 degrees.

After measuring, place the thermometer in 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, tumor diseases, intestinal diverticulosis.
Symptoms indicating the presence of a chronic anal fissure: bloody discharge after defecation, pain before and after defecation. A proctologist will detect this disease during a routine visual examination.
Sharp, intense pain in the rectal area, poor general health and increased temperature with signs of intoxication are indications for calling emergency services. The following symptoms may indicate inflammatory process subcutaneous fatty tissue - paraproctitis.
The reasons for contacting a specialist are nonspecific symptoms, characteristic of many diseases of the rectum (cancer, polyps, hemorrhoids): sudden weight loss, there is an admixture of blood and mucus in the stool, the patient experiences severe pain before and after defecation.