Amongst each of the various modalities of screening (CT Colonography, Colonoscopy, Sigmoidoscopy, etc.), what are the risks associated with each?
Dr. Johnson: Clearly there are risks with any test even those that are viewed as “safe” and individuals should consider the benefits and risks of each screening test or procedure prior to undergoing the examination. This involves not only an assessment of the direct risks of performing the specific test or procedure, but also an understanding of the risks/benefits associated with what may be found or missed should one test be chosen or rejected as an option. Furthermore, one’s assessment should include downstream risks (and costs) of additional tests which may be warranted as a result of the findings for the initial test/procedure. The chief limitation of flexible Sigmoidoscopy is that it does not examine the entire colon. Under optimal conditions, only the rectum, sigmoid and descending colon can be examined. The complications of flexible sigmoidoscopy include colonic perforation, even if no biopsy or polypectomy is performed, but this occurs in fewer than one in 20,000 examinations.
