High risk stigmata and treatment strategy for acute lower gastrointestinal bleeding: a nationwide study in Japan

Background The rebleeding risks and outcomes of endo-scopic treatment for acute lower gastrointestinal bleeding(ALGIB) may differ depending on the bleeding location, type, and etiology of stigmata of recent hemorrhage (SRH)but have yet to be fully investigated. We aimed to identify high risk endoscopic SRH and to propose an optimal endo-scopic treatment strategy. Methods We retrospectively analyzed 2699 ALGIB patients with SRH at 49 hospitals (CODE BLUE-J Study), of whom88.6% received endoscopic treatment.Results30-day rebleeding rates of untreated SRH signifi-cantly differed among locations (left colon 15.5% vs. right colon 28.6%) and etiologies (diverticular bleeding 27.5%vs. others [e.g. ulcerative lesions or angioectasia] 8.9%),but not among bleeding types. Endoscopic treatment re-duced the overall rebleeding rate (adjusted odds ratio[AOR] 0.69; 95%CI 0.49-0.98), and the treatment effectwas significant in right-colon SRH (AOR 0.46; 95%CI 0.29-0.72) but not in left-colon SRH. The effect was observed inboth active and nonactive types, but was not statisticallysignificant. Moreover, the effect was significant for diverti-cular bleeding (AOR 0.60; 95%CI 0.41-0.88) but not for other diseases. When focusing on treatment type, the ef-fectiveness was not significantly different between clipping and other modalities for most SRH, whereas ligation wassignificantly more effective than clipping in right-colon di-verticular bleeding. Conclusions A population-level endoscopy dataset al-lowed us to identify high risk endoscopic SRH and proposea simple endoscopic treatment strategy for ALGIB. Unlike upper gastrointestinal bleeding, the rebleeding risks for AL-GIB depend on colonic location, bleeding etiology, andtreatment modality.