Urgent Versus Standard Colonoscopy for Management of Acute Lower Gastrointestinal Bleeding A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Acute lower gastrointestinal bleeding (LGIB) is a common indication for hospitalization. However, the optimum timing of colonoscopy following patient presentation remains unclear. This systematic review and meta-analysis aims to evaluate the effect of urgent versus standard colonoscopy timing on management of acute LGIB. Materials and Methods: Medline, EMBASE, CENTRAL, and PubMed were searched up to January 2020. Randomized controlled trials were eligible for inclusion if they compared patients with hematochezia receiving urgent (<24 h) versus standard (>24 h) colonoscopy. Nonrandomized observational studies were also included based on the same criteria for additional analysis. Pooled estimates were calculated using random effects meta-analyses and heterogeneity was quantified using the inconsistency statistic. Certainty of evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Results: Of 3782 potentially relevant studies, 4 randomized controlled trials involving 463 patients met inclusion criteria. Urgent colonoscopy did not differ significantly to standard timing with respect to length of stay (LOS), units of blood transfused, rate of additional intervention required, or mortality. Colonoscopy-related outcomes such as patient complications, rebleeding rates, and diagnosis of bleeding source did not differ between groups. However, meta-analysis including nonrandomized studies (9 studies, n=111,950) revealed a significantly higher rate of mortality and complications requiring surgery in the standard group and shorter LOS in the urgent group. Overall GRADE certainty of evidence waslowin the majority of outcomes. Conclusions: Timing of colonoscopy in acute LGIB may not significantly affect patient outcomes. Timing should therefore be decided on a case-by-case basis.