A current approach to rectal bleeding.
The source of bleeding from the rectum is extremely difficult to specify in many patients with moderate to severe bleeding. Lesions may be located anywhere along the gastrointestinal tract. On the basis of the available literature and reported clinical data, we conclude that moderate to severe rectal bleeding originates from the upper gut in up to 10% of patients, from the small bowel in up to 5%, and from the colon in the remaining 85%. Diverticulosis and vascular dysplasia account for 30-50% of colonic bleeding, and inflammatory bowel disease and ischemic colitis for another 5-15%. No diagnosis is made in 20-30% of patients with moderate to severe rectal bleeding. Patients with rectal bleeding can be classified as those whose bleeding stops spontaneously, those whose bleeding stops and then recurs, and those whose bleeding continues despite conventional treatment. Based on these classifications, we present an approach to the diagnosis and therapy of rectal bleeding.