Objectives To assess the sensitivity of double contrast barium enema (DCBE) for diagnosing colorectal cancer (CRC).

Design Retrospective evaluation of DCBE performed in the 2 years prior to diagnosis of CRC.

Setting Teaching hospital in Cambridge, UK.

Patients 1310 consecutive cases of CRC identified from cancer registry data.

Interventions DCBE and colonoscopy.

Main outcome measures Sensitivity of DCBE for diagnosing CRC.

Results 215 patients had undergone a DCBE within the 2 years prior to diagnosis with CRC. After excluding those reported as inadequate, 37 of these were reported as normal, giving a sensitivity of 83% (81–85%).

Conclusions The performance of DCBE is inadequate for the exclusion of CRC. Expansion of colonoscopy and CT colonography capacity is urgently required nationally so that DCBE can finally be abandoned as a firstline test in patients at risk of CRC.