Does colonoscopy save lives?

A recent study suggests it might, but it isn't the last word.

The wisdom of colonoscopy screening seems obvious. The test enables a physician to examine the lining of the entire colon and to remove small, potentially precancerous growths called polyps during the exam. As a result, it has the potential not only to detect colon cancer early, but also to prevent new cases by removing polyps. It is generally assumed that colonoscopy saves lives because the procedure is good at detecting early disease.