Prevention through screening could save the lives of 60 percent or more of those who will be diagnosed. Could you be one of them? The key myth about colorectal screening is than an unpleasant sigmoidoscopy or colonoscopy is the only way it's done. Talk to your doctor about an at-home smear test called a fecal occult blood test. This test is not a substitute for a colonoscopy, especially if you have had polyps found in a past colonoscopy. However, this test could still have your life if there is evidence of blood in the stool, which signals the need for a more complete examination.