This issue of Gut reports a very interesting article by Hol and colleagues1 (see page 62) which compares the results of a randomised controlled trial (RCT) of a 3-day guaiac-based faecal occult blood test (gFOBT), a 1-day immunochemical faecal occult blood test (FIT), and flexible sigmoidoscopy (SIG) for the screening of colorectal cancer (CRC). This is the first study to compare the three tests contemporarily by an RCT as far compliance and detection rates (DRs) of tests are concerned. For this reason the paper is positioned at a crucial point in the discussion on CRC screening.

Several RCTs have been successfully concluded demonstrating the efficacy of gFOBT screening in reducing CRC mortality (range, 13–33%).2 Considering the limited impact of the gFOBT on mortality reduction, FITs have been introduced and several studies3 have demonstrated that FITs are more accurate than the gFOBT.

Moreover, in the last two decades SIG has been proposed as a screening test for CRC based on the assumption that distal colonic significant neoplasia may be predictive of possible proximal neoplasia.4 5 6 In the existing literature SIG DRs proved to be consistently higher than FIT or gFOBT DRs as far as single rank of screening was considered.7 Participation in SIG screening is usually low, at about 30%,5 6 7 with the notable exception …