Linked color imaging (LCI) and magnifying blue laser imaging (BLI) are two new imaging systems used in endoscopy which are recently developed. BLI was developed to compensate for the limitations of NBI. BLI shows a bright image of the digestive mucosa, enabling the detailed visualization of both the microstructure and microvasculature. However, BLI still is not able to obtain sufficient brightness for distant lesions. The newly developed LCI system (FUJIFILM Co.) creates clear and bright endoscopic images by using short-wavelength narrow-band laser light combined with white laser light on the basis of BLI technology. LCI makes red areas appear redder and white areas appear whiter. Thus, it is easier to recognize a slight difference in color of the mucosa. This is a study to determine if using LCI of the colon, rather than the usual white light on the colon, will improve the detection of flat adenomas and serrated polyps. The polyps are called serrated because of their appearance under the microscope after they have been removed. They tend to be located up high in the colon, far away from the rectum. They have been definitely shown to be a type of precancerous polyp and it is possible that using LCI will make it easier to see them, as they can be quite difficult to see with standard white light. LCI/BLI enables endoscopists to accurately describe the pit pattern of adenomas. By comparing White Light Endoscopy and LCI/BLI, it will show if there is any comparable advantage to using one or the other for lesion detection and assessment.

This is a randomized controlled trial comparing the use of linked color imaging (LCI) and magnifying blue laser imaging (BLI) versus standard white light for the detection of serrated lesions in the proximal colon (the colon proximal to the splenic flexure). The proximal colon has large intestine and many folds which will lead missing flat lesions. Recent studies have indicated that colonoscopy is more effective in preventing cancer in the left side of the colon than the right side of the colon. The reasons for this difference may be partly biologic, in that a special group of polyps known as serrated polyps, particularly sessile serrated adenomas, are located primarily proximal to the splenic flexure. These lesions are endoscopically subtle in that they are often flat, have the same color as the surrounding mucosa, and are hard to differentiate from normal mucosa. LCI makes red areas appear redder and white areas appear whiter. Thus, it is easier to recognize a slight difference in color of the mucosa. This study will test whether LCI will increase the detection of serrated lesions in a randomized controlled trial.

Inclusion Criteria:

--Consecutive adult patients undergoing an outpatient colonoscopy

Exclusion Criteria:

• unable to provide informed consent
• had undergone prior resection of the colon
• inflammatory bowel disease
• familial adenomatous polyposis, Peutz-Jeghers syndrome or other polyposis syndromes.