 The biopsy protocol is meant to reflect observed mucosal abnormalities and, in the case of conventional colonoscopy, it will be supplemented by random samples taken every 10 cm of the colon. A standard biopsy forceps will be used Radial Jaw 4, Boston Scientific Inc., USA. To reduce the risk of sampling error, a minimum of two biopsies for each suspicious lesion will be performed. The number of lesions suspect of neoplasia will be noted and targeted by each procedure. In the case of high-resolution FICE colonoscopy, an analysis of the surface pattern will be performed for each targeted lesion according to the pit pattern classification. Suspicious FICE lesions will be defined as having a polyploidy, flat or irregular mucosal structure with Kudo pit pattern III - V, unusual ulcers, strictures or areas with increased and disrupted vascular intensity revealed by dark colorationdiscoloration and confirmed with magnification annexe 9. In conventional endoscopy without FICE, suspicious lesions will be defined as polypoid or irregular mucosa, and unusual ulcers or strictures. During the conventional white light endoscopy but not during FICE additional four-quadrant random biopsies will be taken every 10 cm of colon and placed in a specimen container of formalin. Targeted biopsy samples will be sent separately for analysis. 