title: Two unusual causes of massive colonic bleeding.
mesh_terms: D000328:Adult; D000368:Aged; D019867:Anti-Glomerular Basement Membrane Disease / Q000150:complications*; D003108:Colonic Diseases / Q000209:etiology*; D006471:Gastrointestinal Hemorrhage / Q000209:etiology*; D006801:Humans; D008297:Male; D014456:Ulcer / Q000150:complications* / Q000601:surgery