Background: Current U.S. guidelines recommend colonoscopy within 24 hours for patients presenting with high-risk or severe acute lower gastrointestinal bleeding. However, prior meta-analyses of the timing of colonoscopy relied primarily on observational studies, and a recent multicenter randomized, controlled trial suggests no substantial benefit for early colonoscopy.
Study design: Systematic review and meta-analysis of randomized, clinical trials.
Setting: English language literature search from MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials, performed in July 2019.
Synopsis: The authors identified four randomized, controlled trials that compared early colonoscopy (defined as within 24 hours) with elective colonoscopy (defined as beyond 24 hours) and/or other diagnostic tests for patients presenting with acute lower GI bleeding. They performed a meta-analysis, including 463 patients, which showed no significant difference in risk of persistent or recurrent bleeding for early versus elective colonoscopy. The authors also found no significant differences in secondary outcomes of mortality, endoscopic intervention, primary hemostatic intervention, or identification of bleeding source. Limitations of this research include the relatively small number of studies included, and potential for selection bias in the original studies. Notably two of the four studies included were prematurely terminated before their planned sample sizes were reached.
Bottom line: In patients hospitalized with acute lower GI bleeding, colonoscopy within 24 hours may not reduce further bleeding or mortality when compared with elective colonoscopy.
Citation: Tsay C et al. Early colonoscopy does not improve outcomes of patients with lower gastrointestinal bleeding: Systematic review of randomized trials. Clin Gastroenterol Hepatol. 2019 Dec 13..
Dr. Hu is a hospitalist at Beth Israel Deaconess Medical Center, and instructor in medicine, Harvard Medical School, both in Boston.