<prompt> Massive bleeding per rectum in a 70 yr old patient is due to ?DiveiculosisCarcinoma colonColitisPolyps  <response>: Ans. is a i.e., Diveiculosis Causes of lower GI bleed in adults 1 Local anorectal diseases - hemorrhoids most common, anal fisures.2 Diveiculosis 2nd MC3 Vascular ectasias, angiodysplasias4 Neoplasm polyps adenocarcinoma5 Colitis Ischemic, infectious, IBDAlthough hemorrhoids are the MC cause of bleeding per rectum, it causes small bleed.Diveiculosis is the MC cause of massive bleeding per rectum.Diveicular bleeding is abrupt in onset usually painless, sometimes massive, and often from the right colon. The bleeding stops spontaneously in approx. 80 of patients and rebleeds in 20-25 of pts. 