Pros and cons of colonoscopy in management of acute lower gastrointestinal bleeding

Acute lower gastrointestinal bleeding (LGIB) is a frequent gastrointestinal cause of hospitalization, particularly in the elderly, and its incidence appears to be on the rise. Endoscopic and radiographic measures are available for the evaluation and treatment of LGIB including flexible sigmoidoscopy, colonoscopy, angiography, radionuclide scintigraphy and multi-detector row computed tomography. Although no modality has emerged as the gold standard in the management of LGIB, colonoscopy is the current preferred initial test for the majority of the patients presenting with hematochezia felt to be from a colon source. Colonoscopy has the ability to diagnose all sources of bleeding from the colon and, unlike the radiologic modalities, does not require active bleeding at the time of the examination. In addition, therapeutic interventions such as cautery and endoclips can be applied to achieve hemostasis and prevent recurrent bleeding. Studies suggest that colonoscopy, particularly when performed early in the hospitalization, can decrease hospital length of stay, rebleeding and the need for surgery. However, results from available small trials are conflicting and larger, multicenter studies are needed. Compared to other management options, colonoscopy is a safe procedure with complications reported in less than 2% of patients, including those undergoing urgent examinations. The requirement of bowel preparation (typically 4 or more liters of polyethylene glycol), the logistical complexity of coordinating after-hours colonoscopy, and the low prevalence of stigmata of hemorrhage complicate the use of colonoscopy for LGIB, particularly in urgent situations. This review discusses the above advantages and disadvantages of colonoscopy in the management of acute lower gastrointestinal bleeding in further detail.