['Poor standards in colonoscopy services and the introduction of a colorectal cancer screening program in the United Kingdom have highlighted the need to establish high-quality training and competency assessments in colonoscopy. The aims of this study were to evaluate the effectiveness of a 1-week hands-on colonoscopy course utilizing novel assessment tools.', "Twenty-one doctors with varying colonoscopy experience who attended an accelerated colonoscopy training week (ACTW) were prospectively studied. They were trained and assessed in key aspects of colonoscopy. Knowledge was assessed with a multiple choice question (MCQ) paper. Practical hand skills were taught and evaluated using a computer simulator and live case teaching. Actual colonoscopy performance was assessed using Direct Observation of Procedural Skills scores (DOPS) and an objective tri-split video score of insertion technique. Two independent trainers taught and assessed the trainees at the start and end of the ACTW and at a median of 9 months' follow-up.", 'Following training there were significant improvements in the MCQ score (P < 0.001), the simulator test case times (P = 0.02, P = 0.003), and the global DOPS score (P < or = 0.02). All improvements following the accelerated training were sustained at a median follow-up of 9 months.'] Does intensive training over 5 days improve colonoscopy skills long-term?