We read the article by East et al (Gut 2007;57:65–70) with great interest. Their study included high yields of flat adenomas in the proximal colon using newly developed narrow band imaging (NBI). Other than their study, two others have reported that the use of NBI improves polyp detection;1 2 however, these studies did not include any depressed-type colorectal neoplasia which has been detected not only in Japan but also in Western countries. It is important to detect depressed-type neoplastic lesions during colonoscopy as they tend to invade …