<prompt> Rectal polyp most commonly presents asObstructionBleedingInfectionChanges into malignancy  <response>: .LOWER GI BLEED- Bleeding in the GIT below the level of the ligament of Treitz. Normal faecal blood loss is 1.2 mlday. A loss more than 10 mlday is significant. Angiodysplasia. Diveicular disease - commonest cause in Western countries. Tumours of colon or small bowel. Anorectal diseases--Haemorrhoids, fissure in ano. Ulcerative colitis Crohns disease. Colorectal polyps; rectal carcinomas. Intussusception ref:SRB;s manual of surgery,ed 3,pg no 925. 