Philip Hendy reviewing Clark et al.1This prospective open-label study stratifies adenomatous polyp ‘miss rates’ by means of a second-look colonoscopy according to the quality of bowel preparation (using a validated bowel preparation scoring system). The study defines minimum standards that should be met, thus clarifying which patients should receive an additional colonoscopy due to inadequacy of bowel preparation.

Colonoscopy is routinely used in the screening and surveillance of colorectal cancer and is effective at reducing incidence and mortality (mortality ratio 0.47).2 The aim being to detect cancers at an earlier stage (survival is over 90% when detected early) and to remove adenomas before they progress to malignancy. Inadequate bowel preparation leads to missed lesions, while lack of confidence about what constitutes acceptable preparation leads to inappropriately shortened intervals of colonoscopy. Little work has been done, however, to define the minimum standards needed for an examination to be acceptable and below which repeat investigation would be mandatory.

This prospective, non-randomised, partially blinded study was based in a single medical centre (a veterans’ male only hospital) in the USA. Consecutive patients between the ages 50 and 75 undergoing screening …