 Narrow Band Imaging NBI with high-definition HDTV visualization has been implemented into GI endoscopy with the purpose to better highlight endoluminal pathological structures by improving their contrast. Previous studies from referral centers could not show significant differences in terms of colonoscopic adenoma detection rate, but either very high adenoma rates or some numerical differences suggested that some benefit may exist which may become evident with average adenoma rates andor large case numbers. 