To the Editor:— In their recent article, Dodou and de Winter underlined that all types of distal lesions are predictive of proximal neoplasia (PN).1 This conclusion is especially important for colorectal cancer screening. If so, colonoscopy should be performed instead of flexible rectosigmoidoscopy. Risk of advanced proximal colon neoplasm progressing to fatal cancer is relatively low (1 % per year).2,3 On the other hand we must remember that lesions can be missed even in colonoscopy especially flat ones that may progress more rapidly to cancer. Cost of colonoscopy is another issue of concern for patients with distal lesions.