This study evaluates the ability of endoscopists to perform a complete optical diagnosis of colorectal polyps between 5 and 15 mm, and the impact of the only endoscopic diagnosis on the follow-up program for those patients. This is a prospective study in which we compare the diagnosis regarding size and histology made by the endoscopist versus de pathologic diagnosis.

Background: Optical diagnosis of colonic polyps is an attractive possibility and a common practice. However, recommendations and the main decision concerning patients' management still rely on histological diagnosis, with controversial results in previous studies, usually designed to analyze the accuracy of this diagnosis in the setting of a 'resect and discard' or 'diagnose and leave' strategy. However, little has been studied on this diagnosis on polyps of about 10 mm, the threshold for the consideration as a high risk adenoma, that need a 3 year colonoscopy, or, in case of a smaller adenoma, with a recommended revision in 5 years. Some studies have addressed the accuracy when estimating the polyp size, and others the histology by means of virtual or optical chromoendoscopy, but no one has studied both parameters, that are the two pillars in which a revision program for the patient is decided.

Hypothesis: Our main purpose is to determine the accuracy of the complete optical diagnosis as made by the endoscopist in the endoscopy room, in order to give recommendations immediately after the colonoscopy, with no need of further histological analyses.

Aims:

• To establish endoscopist accuracy, in different hospital settings, to predict size and histology of polyps between 5 and 15 mm and whether follow-up recommedations based on this diagnosis are accurate enough, when compared to the pathologic diagnosis.
• To evaluate accuracy of the optical size estimation by the endoscopist, with respect to the measurement after resection and by the pathologist (after formaline fixation).
• To analyze the rate of sessile serrated adenoma not diagnosed by the endoscopista on site.
• To determine the proportion of incomplete resection and complications with different resection techniques.
• To follow-up patients with high risk adenoma with the aim to establish the best follow-up schedule for those patients, and clarify this topic, still subjected to uncertainty.

Inclusion Criteria:

• Age between 18-80 years
• Colorectal polyps with an estimated size (endoscopist estimation) between 5 and 15 mm.
• Consent to be included in the protocol.

Exclusion Criteria:

• Polyps sized <5 mm or >15 mm
• Polyps that cannot be resected.
• Polys that cannot be sent for pathologic study.
• Peacemeal resection.
• Polyposis syndromes with a previous histologic diagnosis.
• Patients do not consent to participate in the study.

Patients that come to the endoscopy unit for colorectal cancer screening or with a specific clinical indication during the study period, in any of the participating hospitals.