Data Sources: The human subject English language literature for the past 15 years, searched using MEDLINE and the terms ''poly-,'' ''adenoma-,'' and ''polypectomy-colorectal.'' Study Selection: The titles and abstracts of all pertinent articles were reviewed. All randomized controlled trials and large case-control and cohort studies related to colorectal polyps were reviewed in depth.

Data Synthesis: Evidence was evaluated along a hierarchy with randomized controlled trials receiving the greatest weight. Conclusions and recommendations were reviewed by a large group of experts in gastroenterology, radiology, and pathology and were circulated for comment to primary care medical societies.

Conclusions: Most patients with polyps should undergo colonoscopy to excise the polyp and search for synchronous neoplasms. Small polyps (<0.5 cm) require individualization. A hyperplastic polyp found during proctosigmoidoscopy is not an indication for colonoscopy. Large sessile polyps require careful follow-up to ensure complete resection. The need for further treatment of a resected polyp with invasive carcinoma depends on several well-defined clinical and pathologic criteria. Follow-up surveillance after polypectomy should be tailored to the individual risk assessment for each patient. Initial follow-up should be performed at 3 years for most postpolypectomy patients. After one negative result of a 3-year examination, the interval can be increased to 5 years. Patients with one small tubular adenoma do not have an increased risk for cancer, and therefore follow-up surveillance may not be indicated. Adoption of these recommendations should substantially reduce the cost of postpolypectomy surveillance and of screening for colorectal cancer.