Colonoscopy is recognised as the standard method for finding and removing colorectal adenomas, which are precursors of most colorectal cancers. It has been shown that there is a direct correlation between adenoma detection rate and the risk of developing colorectal cancer subsequently. However, patients undergoing colonoscopy are still at risk of developing colorectal cancer, mainly because precursor lesions are missed during the procedure. This may be due to insufficient bowel preparation, difficulties in visualising flat lesions or the location of lesions behind haustral folds.