Screening and surveillance for colorectal neoplasia: uncertainties of colonoscopic management.

Over the past decade the use of screening and surveillance modalities has been associated with a small but significant decrease in the incidence of colorectal cancer and an increase in curability of lesions that are found. Although consensus-based international guidelines have stressed the variety of possible diagnostic options that can serve this purpose, in many countries colonoscopy withremoval of all polyps has become the test of choice. The evidence-base for this choice is largely derivative rather than direct and prospective, and many uncertainties remain in its use as a primary screening modality. This review examines our current guidelines relative to risk stratifying the populations offered the test; the onset, interval, and discontinuation of testing; and the important role of operator variability in outcome.