The small polyp at flexible sigmoidoscopy: an historical perspective on why practices still vary

Current practices vary regarding the approach to small polyps discovered during screening flexible sigmoidoscopy. The most common practice is to perform colonoscopy whenever any adenoma is detected, a strategy that generally uses biopsy of polyps < or = 5 mm in size. However, data suggest that tubular adenomas < 1 cm in size in the distal colon have less predictive value than other distal adenomas for advanced adenomas in the proximal colon. Thus, some centers reserve colonoscopy for distal adenomas with tubulovillous or villous histology, > 1 cm in size, or with high-grade dysplasia. At the other end of the spectrum, another school of thought advocates screening colonoscopy, recognizing that most patients with advanced proximal adenomas do not have polyps in their distal colon. Advocates of this approach use any excuse to perform colonoscopy, whether it be a positive fecal occult blood test, minor symptoms, or small polyp at flexible sigmoidoscopy, even if hyperplastic. This review describes the history of the controversy regarding management of findings at flexible sigmoidoscopy, the data pertinent to the controversy, and the basis for the three approaches described above, all of which are currently within the standard of medical care.