Lower GI bleeding: epidemiology and diagnosis.

Lower gastrointestinal bleeding is one of the most common gastrointestinal indications for hospital admission, particularly in the elderly. Diverticulosis accounts for up to 50% of cases, followed by ischemic colitis and anorectal lesions. Though most patients stop bleeding spontaneously and have favorable outcomes, long-term recurrence is a substantial problem for patients with bleeding from diverticulosis and angiodysplasia. The management of LGIB is challenging because of the diverse range of bleeding sources, the large extent of bowel involved, the intermittent nature of bleeding, and the various complicated and often invasive investigative modalities. Advances in endoscopic technology have brought colonoscopy to the forefront of the management of LGIB. However, many questions remained to be answered about its usefulness in routine clinical practice. More randomized controlled trials comparing available diagnostic strategies for LGIB are needed.