 Prior to the implementation of population screening in the United Kingdom a colonoscopy quality survey was carried out. The results were appalling, with low completion rates and too many complications, and this led to a nationwide quality improvement programme, which includes systematic data monitoring and a very comprehensive training effort. All NHS endoscopy providers are invited to participate and there is regular feedback on quality data both at the endoscopy service level and at the individual colonoscopists level. This has led to a marked improvement in the overall quality. 