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

To establish the sensitivity of double contrast barium enema (DCBE) for det ection of colorectal carcinoma in a tertiary referral centre and consider i ts possible role as a suitable imaging method in screening for this disease . A total of 160 patients with a histopathologically proven diagnosis of colo rectal carcinoma over a two year period were reviewed. Subsequently 112 of the 160 patients were identified as having undergone DCBE, the results of w hich were analysed to determine its sensitivity for detecting colorectal ca rcinoma. Colorectal carcinoma was missed in 4 of the 112 barium enemas performed. Th is 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 an d D were missed, with tumours located in the right and the sigmoid colon. T he mean delay to operation in these four cases was 6 weeks. Our study corre lates with previous studies showing a false negative rate for DCBE of 3.5%, Colonoscopy also fails to detect small numbers of tumours with false negat ive rates reported as high as 10%. We suggest that double contrast: barium enema should be effective as a screening method in any future colorectal ca ncer screening program.