Colorectal cancer — which includes both colon and rectal cancer — occurs when cells in the colon and/or rectum begin to grow out of control. The colon and rectum are parts of the large intestine, which is in turn part of the digestive system. Colorectal cancers tend to begin as growths, known as polyps, on the inner lining of the colon or rectum. While not all polyps become cancerous, some can develop into cancer over time, usually several years. If not treated, a cancerous polyp can grow into the wall of the colon or rectum and then spread.
While colorectal cancers are one of the most common types of cancers and the third leading cause of death from cancer in America, there are steps you can take to help prevent colorectal cancer.