Backgroud/Aims: The purpose of this study was to examine the clinical observations of patients with hematochezia in attempt to determine the appropriate evaluation and treatment of this group of patients. Methods: Seventy patients with hematochezia were admitted to Intemal medicine (IM) Department of Chungnam National University Hospital from January 1990 to August 1997. The clinical observations of patients with hematochezia were reviewed and the results are as follows. Results: 1) The causes of the hematochezia were ischemic colitis (18.6%), hemorrhoids (15.7%), ulcerative colitis (14.3%), unknown (12.8%), rectal cancer (7.1%), nonspecific ulcers (rectum; 4.3%, colon; 1.4%), diverticulosis (5.7% ), colon cancer (4.3%.), mdiation colitis (2.9%), angiodysplasia (2.9%), polyps (2.9%), Samonella colitis (2.9%), rectal varix (1.4%), ileitis(1.4%) and ileal ulceration (1.4%). 2) The average hemoglobin of the patients with hematochezia was 9.6 g/dl. Forty percent of the patients with hematochezia required a transfusion and the average transfusion amount was 4.4 packs (Pack Red Cell). Patients with nonspecific ulcers (recutum, colon), angiodysplasia, colon cancer, ilieal lesion and rectal varix required more transfusions (average transfusion amount, 5.7 packs). 3) Patients who improved with eonservative treatment only were 85.7%, and 11.4% required surgical intervention. Also 2.9% required endoscopic intervention. 4) Confirmative modalities of hematochezia included colonoscopy (80%), and others (angiography, barium enema, and operation etc.). Conclusions: In patients with hematochezia admitted to the IM Department, the cause of hematochezia was confirmed by colonoscopy and patients with hematochezia were mainly managed using conservative treatment. (Korean J Gastrointest Endosc 18: 853-862, 1998)