Every year more than 140,000 Americans are diagnosed with colon cancer, and more than 50,000 will die from the disease. But a colonoscopy can help prevent that. In fact, research published March 5, 2013, in Annals of Internal Medicine found the test can reduce the likelihood of advanced colorectal cancer diagnosis by 70% in adults with average risk. "This study is reassuring. Prevention of late-stage cancers, which usually go on to cause death, was substantial in both the right and the left colon. Even stronger studies, randomized controlled trials, are under way, but it will be many years before their results are available," says Dr. Robert Fletcher, one of the study authors and professor emeritus at Harvard Medical School. A colonoscopy is an outpatient procedure that allows a gastroenterologist to examine the inside of your colon and rectum. It's done with a thin, flexible tube with a camera on the end, which is inserted through the anus. The doctor looks for and removes small growths called polyps, which can turn into cancer. The National Cancer Institute recommends colonoscopy screenings for all adults starting at age 50, with follow-ups every 10 years, or more often if the risk for cancer is higher. People with a parent or sibling who had colon cancer should be screened before age 50. Other screening tests for colon cancer include flexible sigmoidoscopy, virtual colonoscopy, and a fecal occult blood test. Talk to your doctor about which is right for you.