COLONOSCOPY IN THE INVESTIGATION OF COLONIC DISEASES

A retrospective analysis of 640 patients who underwent 681 colonoscopi c examinations between March 1984 and April 1996 was undertaken, The m ajor indications were rectal bleeding (32.8%), change in bowel habit ( 24.7%), abdominal pain (20.1%), abnormal barium enema (9.8%) and iron deficiency anaemia (4.8%). Total colonoscopy was performed in 79.3% of cases, The colonoscopic finding was normal in 49.8% of patients, Most of the lesions were benign, Polyps and carcinoma were found in 9.2% a nd 7% of patients respectively. 91.3% of the lesions were located dist al to the splenic flexure and of the remaining proximal lesions, polyp s and carcinoma accounted for only 2.2%. Rectal bleeding produced the highest diagnostic yield (70%) followed by iron deficiency anaemia (61 .3%), change in bowel habit (48.1%) and abnormal barium enema (47.6%), Lower yields were found in patients with abdominal mass (33.3%), foll ow up colonoscopy (28.6%) and abdominal pain (26.9%). However, the dia gnostic yield of clinically significant pathology varied widely among the different indications, Therefore, selection of patients for colono scopy based on the diagnostic yield of each indication may not be prac tical, Sigmoidoscopy is suggested as the first line of investigation f or patients suspected to have colonic diseases, particularly where the re is limited trained manpower and facility, Total colonoscopy should be reserved for sigmoidoscopy negative patients with persistent sympto ms and high risk cases for malignancy.