The primary endpoint of AMR was chosen as this measure appears to be related to the performance of colonoscopy and reduction in colorectal cancer incidence. During the course of the last decade, several major visualizations studies have been performed and it has become common practice to use the "second-pass" method for measuring colonoscopy visualization methods, iii, iv. In the "second-pass" method, during the course of the first colonoscopy, all visualized lesions are removed (or tattooed in the event that they cannot be removed for any reason.). Any unmarked abnormalities discovered during the second pass colonoscopy are considered to be missed pathologies for the first pass colonoscopy.