Colonoscopy for investigation of unexplained rectal bleeding in a tropical country.

One hundred and forty four patients underwent colonoscopy to detect the cause of rectal bleeding. This was successful in either identifying the lesion or excluding the presume of lesions up to the cecum in 88.8% patients. The source of bleeding was diagnosed in 106 (73.61%) patients. Predominant lesions were nonspecific colitis and ulcers (62.26%), polyps (17.92%), cancer (8.49%), rectal varices (3.77%) and tuberculosis (1.88%). The remainder had other colonic conditions such as radiation colitis, ischemic colitis, vascular malformation, diverticulosis, right sided ulcerative colitis and pseudo-pancreatic cyst communicating with the descending colon. The majority (94.33%) of these lesions involved the left colon. Thus colonoscopic examination was useful in localizing the cause of rectal bleeding and the predominant lesions were differed from those reported in the western hemisphere.