In the beginning of the colonoscopy era, this technique was accepted as the most accurate method of investigation for the large bowel. Since then, studies have shown that colonoscopy may miss lesions that may be responsible for cancer of the right colon. Endoscopists have tried several methods for increasing the ability to visualize the right colon, including retroflexion of the colonoscope. However, this procedure frequently cannot be performed in the right colon and often cannot be performed in the narrowed left colon. A novel device, the TER, has been introduced to find lesions hidden behind the proximal aspect of folds in the colon. Use of this device has been associated with increased detection of adenomas in the colon. This device is introduced through the instrumentation channel of a standard colonoscope, providing a retrograde view of the colon as the straightforward colonoscope visualizes the distal portions of folds. This device holds promise for discovery of most, if not all, of the adenomas in the colon, though additional research is necessary.