Why is colonoscopy the best test to screen the colon and rectum?
Colonoscopy is more accurate that a barium x-ray exam of the colon to detect polyps or early cancer. It is better than a flexible sigmoidoscopy because it looks at the entire colon, and not just the left side as with a flex sig. This is becoming more of an issue as there is an increased incidence of colon cancer on the right side of the colon over the past several decades. It is better than virtual colonoscopy because if polyps are found on colonoscopy, they are removed right then and there. A positive finding on virtual colonoscopy means you have to repeat the prep (the worst part about any colon screening test) and go through a colonoscopy anyway.
