Colon cancer occurs in the large intestine (AKA the colon) or rectum. Abnormal growths (called polyps) can form in there, and over time, these polyps can turn into cancer. So how do you know if you have polyps? Screening tests can find them, and if you find them early enough, they can be removed before becoming cancerous. Browse the categories below to learn your options when it comes to screening and early detection.