Objectives: To study an individual s experience of either flexible sigmoidoscopy (FS) or colonoscopy in a colorectal cancer prevention programme. Methods: Consecutive individuals in a Bowel Cancer Prevention Programme, who had either an unsedated FS or a colonoscopy with sedation, participated in a prospective cross-sectional questionnaire-based study. Results: A total of 447 responses were obtained for 256 colonoscopies and 191 FSs (200 men [45 and 247 women [55 ). The overall experience of colonoscopy was more comfortable than FS (75 versus 18 ; P <0.001). Embarrassment was low for both procedures (8 ). There was no pain associated with colonoscopy and most individuals had a pain score of less than 3 (11-point scale) for FS: 72 of men, 55 of women (P <0.001). Most individuals did not have a gender preference for the endoscopist. For colonoscopy, the worst part of the procedure was the preparation (78 ) and for FS the preparation and the procedure ranked equally worst (30 ). Conclusions: We have shown that colonoscopy with sedation is a very comfortable procedure. FS is more uncomfortable than colonoscopy; however, for the majority it is a tolerable experience. Women found FS only slightly more painful than men. The worst part of either procedure was the preparation. Embarrassment with either procedure was minimal. Both procedures are well tolerated and suitable for colorectal cancer screening.