In the future, it may be possible to look for these mutations in a small stool sample, and when they're found, then perform additional diagnostic tests to identify the polyps or cancers. That's a great question. Previously, our evidence suggested that when polyps occurred, they started in the rectum or on the left side of the colon. This is why flexible sigmoidoscopy was felt to be an effective screening test. When a polyp was found using a flexible sigmoidoscopy, the patient was then scheduled for a colonoscopy to examine the entire colon and remove any polyps.
Barium enema is an examination of the entire colon using contrast, air and X-rays.
Before the development of our current colonoscopes, it was widely used as an effective way to image the colon. As many of our participants tonight may know, there have been several recent studies showing that colonoscopy is superior to barium enema and more effective at finding polyps on the right side of the colon than flexible sigmoidoscopy. However, flexible sigmoidoscopy and barium enemas still have some effectiveness and are less expensive and have fewer complications than colonoscopy. Although the risks of colonoscopy, which include reaction to the sedation, bleeding, and perforation, are rare, these risks and the cost of the procedure must be considered in population screening. Having said this, many people in the colon cancer community are in favor of a screening colonoscopy.