Double contrast barium enema and colorectal carcinoma: sensitivity and potential role in screening.

To establish the sensitivity of double contrast barium enema (DCBE) for detection of colorectal carcinoma in a tertiary referral centre and consider its possible role as a suitable imaging method in screening for this disease. A total of 160 patients with a histopathologically proven diagnosis of colorectal carcinoma over a two year period were reviewed. Subsequently 112 of the 160 patients were identified as having undergone DCBE, the results of which were analysed to determine its sensitivity for detecting colorectal carcinoma. Colorectal carcinoma was missed in 4 of the 112 barium enemas performed. This corresponds to a sensitivity of 96.5% with a false negative rate of 3.5%. The Dukes Classification in these 4 cases showed that Dukes stage B, C and D were missed, with tumours located in the right and the sigmoid colon. The mean delay to operation in these four cases was 6 weeks. Our study correlates with previous studies showing a false negative rate for DCBE of 3.5%. Colonoscopy also fails to detect small numbers of tumours with false negative rates reported as high as 10%. We suggest that double contrast barium enema should be effective as a screening method in any future colorectal cancer screening program.