There are a few studies regarding Sessile Serrated Lesions (SSL). They are recently identified as precancerous lesions. Yet, digestive tract serrated lesions would be part of a new colic carcinogenesis way : the serrated tumor way. Evolution from polyp to cancer would be faster than through the usual adenoma to cancer way. It would be then responsible of a lot of "missed" lesions or interval cancer. The missed SSL rate is estimated at between 27% and 59%.

Current diagnosis methods show weakness to identify those SSL. In order to improve their detection, the investigators dispose of several coloration techniques. Indigo carmine chromoendoscopy enhance neoplastic lesion detection as part of the hereditary rectal carcinoma screening. NBI electronic coloration, which is faster and easier has not shown any efficacy on the adenoma detection rate, except for patients with Lynch syndrome.

The objective is to better describe the SSL endoscopic semiology (detection and characterization) and to establish standards for the endoscopic techniques in order to improve the colonoscopy diagnosis quality. The investigators propose to evaluate 2 fundamental endoscopic techniques (Narrow Band Imaging (NBI) and indigo carmine), widely used for other indications, in comparison with the White Light technique (WLI).

Therefore, the investigators propose a prospective, observational, multicentric cohort study in order to 1) define SSL endoscopic various aspects 2) establish which technique (white light, Narrow Band Imaging, indigo carmine chromoendoscopy) is the best to diagnose SSL, namely detection and characterization 3) evaluate the multifocal dimension rate for those lesions at ascending colon level.

The diagnosis impact is immediate, and could allow to consider an update for boh endoscopic NICE and Kudo Pit Pattern classification, and good practice guidances for colonoscopic diagnosis. Better SSL detectability thus their systematic resection could have a long term effect in reducing both colon cancer rate and interval cancer

Inclusion Criteria:

• Male or female patients 18 years of age or older
• Patient having an indication for colonoscopy to detect colorectal neoplastic lesions, which meet at least one of the following conditions :
• Positive fecal occult blood test
• 1st degree family history of colorectal cancer or adenoma before 60 years of age
• Personal history of colorectal adenoma or colorectal cancer
• Unexplained digestive symptoms after 50 years of age or those not responding to symptomatic treatment : modification of bowel movements, abdominal pains
• Isolated or repeated rectal bleeding after 50 years of age or occult bleeding
• Acromegaly
• Infectious endocarditis with digestive bacteria
• Suspicion of sessile serrated lesion in the right colon
• None opposite of patient for participating

Exclusion Criteria:

• History of digestive resection as resection of the right colon (right ileocolectomy, right hemicolectomy) or large colic resection.

The population being studied is the cohort of patients referred for a colonoscopy resulting screening indication, digestive syndrome or monitoring.