Ischemic colitis

Ischemic colitis is a transient disorder of blood circulation in the colon.

The blood supply of the large intestine is provided by the superior and inferior mesenteric arteries. The superior mesenteric artery supplies the entire small, cecum, ascending and part of the transverse colon; the inferior mesenteric artery supplies the left half of the large intestine.

In case of ischemia of the large intestine, a significant number of microorganisms populating it contribute to the development of inflammation in the intestinal wall (even transient bacterial invasion is possible). The inflammatory process caused by ischemia of the wall of the large intestine further leads to the development of connective tissue in it and even the formation of fibrous stricture.

The splenic flexure and left colon are most consistently affected in ischemic colitis.

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What causes ischemic colitis?

Necrosis may develop, but is usually limited to the mucosa and submucosa and only occasionally involves the entire wall, necessitating surgical intervention. It occurs mainly in older people (over 60 years) and the etiology is unknown, although there is some association with the same risk factors that apply to acute mesenteric ischemia.

Symptoms of ischemic colitis

Symptoms of ischemic colitis are less severe and develop more slowly than those of acute mesenteric ischemia and include left lower quadrant abdominal pain accompanied by rectal bleeding.

1. Abdominal pain. Abdominal pain occurs 15-20 minutes after eating (especially a large meal) and lasts from 1 to 3 hours. The intensity of the pain varies, and it is often quite severe. As the disease progresses and fibrous strictures of the colon develop, the pain becomes constant.

The most common localization of pain is the left iliac region, the projection of the splenic flexure of the transverse colon, and less often the epigastric or umbilical region.

2. Dyspeptic disorders. Almost 50% of patients experience loss of appetite, nausea, bloating, and sometimes belching of air and food.
3. Stool disorders. They are observed almost constantly and are manifested by constipation or diarrhea, alternating with constipation. During the period of exacerbation, diarrhea is more typical.
4. Weight loss in patients. Weight loss in patients with ischemic colitis is quite regular. This is explained by the restriction of the amount of food and the frequency of its intake (due to increased pain after eating) and the disruption of the intestinal absorption function (quite often, along with ischemia of the colon, there is a deterioration in blood circulation in the small intestine).
5. Intestinal bleeding. Observed in 80% of patients. The intensity of bleeding varies - from blood in the stool to the release of significant amounts of blood from the rectum. Bleeding is caused by erosive and ulcerative changes in the mucous membrane of the colon.
6. Objective abdominal syndrome. Exacerbation of ischemic colitis is characterized by mild signs of peritoneal irritation, tension of the abdominal muscles. Palpation of the abdomen reveals diffuse sensitivity, as well as pain predominantly in the left iliac region or left half of the abdomen.

Symptoms of severe peritoneal irritation, especially those that persist for several hours, suggest transmural intestinal necrosis.

Diagnosis of ischemic colitis

Diagnosis is made by colonoscopy; angiography is not indicated.

Laboratory and instrumental data

1. Complete blood count: marked leukocytosis, left shift in leukocyte count, increased ESR. With repeated intestinal bleeding, anemia develops.
2. Urinalysis: no significant changes.
3. Stool analysis: a large number of erythrocytes, leukocytes, and intestinal epithelial cells are found in the stool.
4. Biochemical blood test: decreased levels of total protein, albumin (with prolonged course of the disease), iron, sometimes sodium, potassium, calcium.

Colonoscopy: performed strictly according to indications and only after the acute manifestations have subsided. The following changes are revealed: nodular areas of edematous mucous membrane of a blue-purple color, hemorrhagic lesions of the mucous membrane and submucous layer, ulcerative defects (in the form of dots, longitudinal, serpentine), strictures are often detected, mainly in the area of the splenic flexure of the transverse colon.

Microscopic examination of colon biopsy specimens reveals edema and thickening, fibrosis of the submucosal layer, its infiltration by lymphocytes, plasma cells, granulation tissue in the ulcer bottom area. A characteristic microscopic sign of ischemic colitis is the presence of multiple hemosiderin-containing macrophages.

6. Plain radiography of the abdominal cavity: an increased amount of air is detected in the splenic angle of the colon or other parts of it.
7. Irrigoscopy: performed only after the acute manifestations of the disease have been relieved. At the level of the lesion, a narrowing of the colon is determined, above and below - an expansion of the intestine; haustra are poorly expressed; sometimes nodular, polyp-like thickenings of the mucous membrane, ulcerations are visible. In the marginal areas of the intestine, finger-like imprints (the "thumbprint" symptom) are detected, caused by edema of the mucous membrane; serration and unevenness of the mucous membrane.
8. Angiography and Doppler ultrasonography: a decrease in the lumen of the mesenteric arteries is revealed.
9. Parietal pH-metry of the colon using a catheter with a balloon: allows comparing the pH of tissues before and after meals. A sign of tissue ischemia is intramural acidosis.

The following circumstances help in the diagnosis of ischemic colitis:

• age over 60-65 years;
• the presence of coronary heart disease, arterial hypertension, diabetes mellitus, obliterating atherosclerosis of the peripheral arteries (these diseases significantly increase the risk of developing ischemic colitis);
• episodes of acute abdominal pain followed by intestinal bleeding;
• the corresponding endoscopic picture of the condition of the colon mucosa and the results of histological examination of colon biopsies;

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Differential diagnosis of ischemic colitis

Ischemic colitis has many common clinical manifestations with Crohn's disease and nonspecific ulcerative colitis: abdominal pain, dyspeptic syndrome, bowel disorders, intestinal bleeding, and the formation of ulcers of the mucous membrane.

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Treatment of ischemic colitis

Treatment of ischemic colitis is symptomatic and includes intravenous fluids, fasting, and antibiotics. Surgery is rarely necessary.

What is the prognosis for ischemic colitis?

Approximately 5% of patients experience recurrence. Sometimes a stricture develops at the site of ischemia, requiring bowel resection.