Making Hematochezia of Unknown Origin Known: A Retrospective Analysis.

INTRODUCTION: Hematochezia is observed frequently in daily practice. However, natural hemostasis often prevents identification of the bleeding source during observations. This study was conducted to clarify risk factors related to rebleeding in hematochezia patients without an identified cause of bleeding. METHODS: We analyzed patients who were admitted to Dokkyo Medical University Hospital during April 1, 2009, through March 31, 2015, with the chief complaint of hematochezia. Main outcome measures included the rebleeding rate and the period until rebleeding in hematochezia patients without an identified bleeding source. RESULTS: We selected 159 patients for analyses. Rebleeding was observed in 46 (28.9%) of 159 patients. The median period until first rebleeding was 166 days (2-3,046 days). Univariate analysis indicated that risk factors for rebleeding were male gender (p = 0.029), higher age (p = 0.023), antithrombotic medicines (p = 0.047), lower hemoglobin on admission (p = 0.024), and the presence of diverticula (p = 0.002). Multivariate analysis indicated the presence of diverticula (p = 0.023) and male gender (p = 0.043) as rebleeding risk factors. DISCUSSION/CONCLUSION: In patients with hematochezia of unknown origin, risk factors for rebleeding indicated in this study, especially the presence of diverticula and male gender, should be given particular attention by physicians.