In many cases, taking the route of a stool sample or virtual colonoscopy is part of an attempt to avoid a traditional colonoscopy. Many patients can feel anxiety around this procedure, however, they are very common and every effective. In fact, Cleveland Clinic reports that traditional colonoscopies can detect 95 percent of cancer cells and large polyps. Should the previous tests have found something, a traditional colonoscopy will likely be required. Bowel prep (laxatives and diet change) is required for this procedure, as is sedation. During this procedure, a lighted and flexible probe goes into the rectum. This is also collecting detailed imaging, like with the virtual colonoscopy. In a traditional colonoscopy, should your doctor find polyps, they can remove them. They can also take tissue samples.