Colon cancer is a serious disease that occurs when cancerous cells originate in the tissues of the colon. As with most cancer, there are usually no early signs of the disease. When symptoms of colon cancer do appear, they can include, among other things, weight loss for no apparent reason, stools that are narrower than usual, vomiting, and feeling very tired. Some tests used to diagnose the cancer include digital rectal exams, fecal occult blood tests (FOBT), and sigmoidoscopies. There are many treatment options available to people with colon cancer, including chemotherapy, surgery, and radiation therapy. Some risk factors for colon cancer include being 50 years of age or older and having a personal history of colon polyps or a family history of colon cancer, rectal cancer, ovarian cancer, uterine cancer, or breast cancer.