Boley and colleagues first described ischemic colitis (IC) in 1963, which was thought to be caused by reversible vascular obstruction of the colon. 1966 Marston et al. clinically classified it into three types, the transient, stenotic, and gangrenous types. In recent years, ischemic colitis has also been clinically classified into non-gangrenous and gangrenous types, where the non-gangrenous type includes transient, reversible IC and non-reversible IC, where non-reversible IC is subdivided into chronic and stenotic IC. IC is a series of clinical symptoms caused by insufficient colonic perfusion to meet the metabolic demands of the colon, ranging from transient self-limiting mucosal and submucosal ischemia to acute fulminant The clinical manifestations of IC are varied, but the typical presentation is abdominal pain followed by blood in the stool.IC is one of the most common lesions of intestinal ischemia, with an estimated incidence of 4.5 to 44 cases per year in 1,000,000 people. Data show that the incidence of IC is higher in the elderly, but it also affects young people from time to time. Moreover, in recent years, the incidence of IC has increased each year with the aging of the population, which has become a common problem for gastroenterologists and surgeons. Studies have shown a correlation between the development of IC and several risk factors. In this study, we analyzed several associated risk factors, of which hypertension and cardiovascular disease were the main ones, accounting for 50.6% (27.1% and 23.5%), constipation for 15.3%, diabetes mellitus for 9.4%, COPD and abdominal surgery for 10.5%, respectively, IBS for 7.1% and colon cancer for 8.2% and vascular lesions for 5.9%. of 85 patients 38 (44.7%) were taking medications (e.g., antihypertensives, digitalis preparations, contraceptives, NASAID, 5-HT3 receptor antagonists, etc.), suggesting that some medications may increase the incidence of IC, but it is unclear whether 5-HT3 receptor antagonists (e.g., alosetron or silansetron) are associated with the incidence of IC, although the FDA reported that the association between the incidence of IC and alosetron was substantially higher than that of the placebo group (0.15 vs 0.0%). In contrast, of the 85 patients with IC in this group, only 6 (7.1%) took the drug for a short period of time. Therefore, further research is needed to determine whether the use of 5-HT3 receptor antagonists is related to the development of IC. The diagnosis of IC is mainly based on clinical symptoms, laboratory tests, imaging, endoscopy and pathology, etc. Laboratory abnormalities in IC include LDH, CPK and amylase elevation, etc. The typical feature of abdominal plain film is the “finger pressure sign” along the intestinal wall, and the typical abdominal CT shows circumferential thickening of the diseased intestinal wall, but they are not specific for the definite diagnosis of IC. IC is not specific. In addition, residual barium from a barium enema can inconvenience subsequent angiography or endoscopy, and also interfere with emergency surgical intervention. Therefore, it has been suggested that colonoscopy coupled with mucosal biopsy pathology is the gold standard for the diagnosis of IC. The microscopic presentation of IC varies with the degree of ischemia. In early ischemia, the microscopy reveals pale, brittle, edematous mucosa, punctate hemorrhage, scattered erosions, segmental erythema with or without ulceration and hemorrhage. The microscopy of moderate ischemia is characterized by linear ulcers or lesions distributed along the longitudinal axis of the colon. In further ischemia, blue-black mucosal nodules may be seen microscopically. Sometimes pseudopolyps and even pseudotumors and pseudomembranes may also be seen. The microscopic features of chronic ischemia are stenosis, loss of the colonic pouch and granular mucosal changes. The colonic blood supply is mainly from the superior and inferior mesenteric arteries and their visceral arterial branches. Colonic ischemia may occur when the colonic blood flow pressure drops below 40 mmHg due to anatomic or functional alterations of the mesenteric vessels in the blood circulation or local blood supply area. Although any part of the colon can be affected by ischemia, the most vulnerable parts of the colon are the “watershred” areas, such as the splenic area, descending colon, sigmoid colon, or recto-basal junction, where blood supply is poor. A study of more than 1,000 patients with IC suggested that about 75% of patients had the left hemicolectomy and about 25% had the splenic region. In our group, the left colon was the lesioned segment in 68 cases (80%). The endoscopic presentation of IC is not specific, so the diagnosis of IC requires a combination of clinical background information and pathology. It should also be differentiated from pseudomembranous enteritis, inflammatory bowel disease and schistosomiasis enteropathy, etc. If the endoscopic manifestation of IC is segmental lesions, clearly demarcated from normal mucosa, and the rectum is rarely affected, it is mostly suggestive of IC. The pathological manifestation of IC is also nonspecific, and mucosal edema, inflammatory cell infiltration, hemorrhage, crypt destruction, intravascular thrombosis, necrosis, granulomatous tissue proliferation with crypt abscesses, pseudopolyposis changes, similar to the presentation of Crohn’s disease. In chronic IC, mucosal atrophy, granulation tissue and iron flavin-rich macrophages are seen. In stenotic IC, transmural fibrosis and mucosal atrophy may be observed. Overall, vitreous degeneration, lamina propria hemorrhage and iron-containing flavin deposition, total mucosal necrosis, and scattered pseudomembranes are more common in IC, which can also be distinguished from pseudomembranous enterocolitis. In conclusion, IC has certain endoscopic manifestations and pathological features, and familiarity with the endoscopic and pathological features of IC can help clinical workers improve the diagnosis and treatment of IC and reduce misdiagnosis. However, since the endoscopic presentation and pathological features of IC are non-specific, it is necessary for clinical workers to combine detailed medical history in order to clearly diagnose IC, and not to lose sight of this. In addition, since the endoscopic manifestations and pathological features of IC have certain similarities with pseudomembranous enteritis, inflammatory bowel disease and schistosomiasis enteropathy, it is especially important to differentiate them in clinical practice.