Inter-endoscopist variation in polyp and neoplasia pick-up rates in flexible sigmoidoscopy screening for colorectal cancer.

Background: The Norwegian Colorectal Cancer Prevention study is an ongoing flexible sigmoidoscopy (FS) screening trial for colorectal cancer. Twenty-one thousand average-risk individuals, aged 50-64 years, living in two separate areas in Norway were randomly drawn from the Population Registry and invited to once-only screening flexible sigmoidoscopy. Examinations were performed over 3 years, at 2 centres, by 8 different endoscopists, using the same type of equipment.