Presence of Melena in Obscure Gastrointestinal Bleeding Predicts Bleeding in the Proximal Small Intestine

Background and Aims Melena is a symptom of upper gastrointestinal bleeding and usually indicates bleeding proximal to the ligament of Treitz. However, whether melena predicts bleeding in the proximal small intestine in patients with obscure gastrointestinal bleeding (OGIB) is unknown and the objective of this study. Methods A retrospective cohort study of consecutive patients undergoing capsule endoscopy for OGIB between July 2009 and May 2016 was conducted. Subjects were categorized based on the presence of melena, and the primary outcome was identification of a bleeding source within the proximal 2/3 of the small intestine. Multi-variable regression was performed to control for confounders. Results During the study, 288 patients met the eligibility criteria. Subjects with melena accounted for 37.1% of the cohort and were more likely to be older (mean age 66.9 vs. 63.9, p = 0.0457), take warfarin (15.1 vs. 9.4%, p = 0.0122), and have a lower 12-month hemoglobin nadir (7.3 vs. 8.3 g/dL, p = 0.0002). On crude analysis, 56.1% of patients with melena had a bleeding source within the proximal small intestine compared to 34.8% for those without (RR 1.61, 95% CI 1.24–2.09, p = 0.0004). On multi-variable analysis, the presence of melena doubled the odds of finding a bleeding site within the proximal small intestine (OR 1.97, 95% CI 1.17–3.33, p = 0.010). Conclusions The presence of melena doubles the odds of finding a bleeding site within the proximal small intestine among patients with OGIB, and deep enteroscopy, if performed before a capsule study, should begin with an antegrade approach in these patients.