The role of early colonoscopy in patients presenting with acute lower gastrointestinal bleeding: a systematic review and meta-analysis.

Objective: The use of early colonoscopy in the management of acute lower gastrointestinal bleeding (LGIB) is controversial, with disparate evidence. We aim to formally characterize the utility of early colonoscopy (within 24 h) in managing acute LGIB.

Design: A systematic literature search to August 2016 identified fully published and abstracts of randomized controlled trials (RCTs) and observational studies assessing early colonoscopy in acute LGIB. Single-arm studies were also included to define incidence. Primary outcomes were overall rebleeding rates and time to rebleeding. Secondary outcomes included mortality, surgery, length of stay (LOS), definite cause of bleeding and adverse events (AEs). Odds ratios (OR) and weighted mean differences (WMD) were calculated.

Results: Of 897 citations, 10 single-arm, 9 observational studies, and 2 RCTS were included (25,781 patients). Rebleeding was no different between patients undergoing early colonoscopy and controls (seven studies, OR = 0.89, 95% CI 0.49-1.62), or RCT data only (OR = 1.00, 95% CI 0.52-1.62). Early colonoscopy detected more definitive sources of bleeding (OR = 4.12, 95% CI 2.00-8.49), and was associated with shorter LOS colonoscopy (WMD = -1.52, 95% CI -2.54 to -0.50 days). No other differences were noted between early and late colonoscopy. AEs occurred in 4.0%, (95% CI 2.9%; 5.4%) of early colonoscopies. Included studies were of low quality, with significant heterogeneity for some outcomes.

Conclusion: Early colonoscopy in acute LGIB does not decrease rebleeding, mortality or need for surgery, but is associated with increased detection of definitive sources of bleeding, shorter LOS, with low complication incidence. However, the quality of evidence is low, highlighting the need for additional high-level studies.