Ischemic colitis is the most common type of intestinal ischemia and has a clinical spectrum of injury that ranges from mild and transient ischemia to acute fulminant colitis. The aim of this study was to explore endoscopic findings and clinicopathologic characteristics of ischemic colitis and be accurate enough to avoid missed diagnosis or misdiagnosis. A retrospective analysis was undertaken of endoscopy findings and clinicopathologic characteristics of 85 cases of ischemic colitis from March 2005 to April 2008 in the endoscopy center of our hospital. All cases underwent colonoscopy with biopsy within 2 weeks of the onset of symptoms, and all specimens with forceps were stained with hematoxylin–eosin and observed under light microscopy. Of the 85 cases of ischemic colitis (24 men and 61 women, average age 61.36 ± 14.49 years old, range 29–84), 71 were over 50 years of age. These cases were associated with the basal diseases such as hypertension, cardiovascular disorders, diabetes, and hematological diseases as well as a history of abdominal operation. The clinical features usually presented with sudden onset of abdominal pain, diarrhea, and hematochezia. Ischemic lesions were located mainly in the left colon with segmental form (only descending colon affected 16%, only splenic flexure 14%, and only sigmoid colon 23%). The 85 patients consisted of the non-gangrenous type (82), which were composed of reversible IC (76) and chronic IC (6), and the gangrenous type (3). Endoscopic appearance of the transient ischemic colitis consisted of petechial hemorrhages, edematous and fragile mucosa, segmental erythema, scattered erosion, longitudinal ulcerations, and sharply defined segment of involvement. Ischemic colitis of stricture was characterized by full-thickness mucosa, lumens stricture, and diseased haustrations. The mucosa of gangrenous colitis with cyanotic and pseudopolyps was endoscopically observed as well. Clinicopathologic characteristics showed mucosal inflammation accompanied by erosion, granulation tissue hyperplasia and gland atrophy, lamina propria hemorrhage, and macrophages with hemosiderin pigmentation in submucosa in particular. Although endoscopy findings and clinicopathologic characteristics of ischemic colitis are nonspecific, colonoscopy with biopsy plays a vital role in the early diagnosis of ischemic colitis.