Approach to Suspected Lower Gastrointestinal Bleeding

Abstract

Acute lower gastrointestinal bleeding (LGIB) is defined as bleeding that originates beyond the ligament of Treitz and accounts for approximately 20 % of all cases of GI bleeding. Diverticular bleeding is the most common source of acute LGIB in the United States. Other frequently encountered sources of LGIB include colonic ischemia, anorectal sources, neoplasia, angiodysplasia, and colitis. Many of the common causes of LGIB present with characteristic clinical features that point to the diagnosis. Hence, a careful clinical history and physical exam can provide vital clues as to the etiology of bleeding and aid in risk stratifying the patient. Early predictors of severity of LGIB include the presence of tachycardia, hypotension, syncope, nonsteroidal anti-inflammatory drugs (NSAIDs) and anticoagulant use, and rectal bleeding within the first 4 h of evaluation, as well as the absence of abdominal pain. Colonoscopy is the preferred initial procedure for the evaluation and potential treatment of LGIB. Evidence suggests that performing colonoscopy early in the hospital course may improve clinical outcomes. New tools, such as high-definition endoscopes, water-jet irrigation systems, large-bore mechanical suction devices, and endoscopic distal attachment caps, have the ability to improve the identification of small or flat lesions in the colon and thus provide better opportunity for therapeutic intervention. New methods, such as the unprepared hydroflush colonoscopy technique, are being developed in order to expedite the performance of early endoscopy and improve the quality of patient care. Further studies are needed to determine the optimal timing of colonoscopy and its role relative to alternative radiologic and therapeutic modalities.

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