<prompt> Least common about angiodysplasia of colon:Involvement of cecumInvolvement of rectum in 50 of casesAffecting age group more than 50 years onlyCause of troublesome lower GI hemorrhage  <response>: Ans. b Involvement of rectum in 50 of casesRef: Sabiston 20th edition, Page 1153Angiodysplasia of colon: Arteriovenous Malformations of bowel Equal in both sexes Affects age group 50 years only Produced massive bleeding from colon in 15 and it is troublesome in diagnosing. Bleeding stops spontaneously in most of them but recurs Most common site is ascending colon and cecum Least common in rectum Treated by endoscopic coagulation or sclerosing agent or intrarterial embolization. Surgical resection is done if not stops -- colectomy. 