HOW USEFUL IS COLONOSCOPY IN LOCATING COLORECTAL LESIONS

Background: It is important to establish the precise location of a col orectal lesion preoperatively. We used a model based on colorectal can cer to assess the efficacy of colonoscopy in locating these lesions. M ethods: We retrospectively analyzed all consecutive new colorectal can cer cases at the Department of Surgery, United Christian Hospital, Kon g Kong, in 1995. Results: Of the 123 cases reviewed by us, 84 cases sa tisfied the analysis criteria. The overall accuracy was 81%. It was es pecially high in the rectosigmoid region (93%) and descending colon (1 00%). The overall predictive power was 83%. Tt was especially high in the right-sided colon (100%) and the rectosigmoid region (93%). Conclu sions: We conclude that colonoscopy is an accurate means for locating lesions in the upper rectum and sigmoid colon. It is also very predict ive of lesions in the upper rectum, sigmoid colon, and right-sided col on.