Colorectal cancer (CRC) is the second leading cause of cancer deaths in the US despite wide use of colonoscopy to prevent CRC-related death. The current explanation for the failure of colonoscopy to prevent most CRC-related death is that lesions are not detected or completely removed. Real-time feedback during colonoscopy has the potential to alert endoscopists that sub-optimal visualization of the colon mucosa is occurring. To determine what type and frequency of feedback most likely will improve colonoscopy, we studied a set of randomly obtained video files for four features associated with quality of visualization: clear or blurry frames, camera speed, amount of remaining debris and effort of the endoscopist to inspect in a circumferential fashion all of the mucosa. Our results show that the two types of feedback most frequently needed to improve visualization are reminders to obtain clear frames or to inspect all of the mucosa in circumferential fashion.