Analysis of the clinical course of chronic ischemic colitis in patients, its timely diagnosis, for the subsequent prevention of the development of «abdominal catastrophe». We analyzed the course of chronic mesenteric ischemia syndrome in 248 (n =100 %) patients. Men – 92 (37.09 %) women – 156 (62.9 %). The average age of patients: 78.3 ± 12.1 (from 66 to 90 years). The analysis of the course of chronic mesenteric ischemia syndrome took place in two stages: retrospective and prospective. Retrospectively, the course of the disease was evaluated in 139 (56.04 %) patients, and prospectively in 109 (43.95 %) patients. There were 90 women (36.29 %), 49 men (19.76 %). In a retrospective group of patients, the course of the disease led to the development of acute mesenteric thrombosis. Of the total number of patients, 22 (15.83 %) survived, 117 (84.17 %) people died. The clinical course of the syndrome of chronic mesenteric circulatory disorders has been studied through a thorough analysis of outpatient charts. Before the manifestation of mesenteric thrombosis, these patients complained of abdominal pain of varying intensity and localization for 4 ± 0.7 years (from 3 to 4.5 years). 109 (43.95 %) patients were examined prospectively. Of these, men – 43 (39.45 %) women – 66 (60.55 %). The average age of the patients was as follows: 76.3 ± 8.7 (from 67 to 85 years). These patients were admitted to the surgical hospital, with suspicion of acute surgical disease, during the examination, urgent surgical pathology was excluded, chronic violation of mesenteric circulation was suspected and a comprehensive examination was conducted for the presence of the latter. The duration of follow-up in this group of patients was 2 years. Diagnosis of ischemic intestinal lesions is difficult and should be carried out not only by colonoscopy, but also using modern diagnostic methods indicating difficulty of mesenteric blood flow. According to its endoscopic signs, ischemic colitis is similar to other inflammatory bowel diseases, so the attending physician should carefully collect and analyze the anamnesis of the disease. In our study, video colonoscopy was the main method of diagnosing ischemic lesions of the colon mucosa.