[Recent problems in colonoscopy for the diagnosis of colorectal cancer].

Colonoscopy is valuable for the correct diagnosis of colorectal cancers and polyps, and it is widely utilized as the routine examination. One of our recent interests in colonoscopy has been how to diagnose minute lesions accurately. For the purpose, magnifying endoscopy using the magnifying colonoscope (type CF-HM and CF-UHM, Olympus), videoendoscopy, endoscopic ultrasonography, and so on, have been evaluated as a future colonoscopy.