Colon cancer is cancer of the large intestine (colon), which is known as the final part of your digestive tract. Most cases of colon cancer starts small, noncancerous (benign) clumps of cells called adenomatous polyps. Over time some of these polyps can become into colon cancer.
Polyps may be small and produce few, if any, symptoms. For this reason, doctors recommend regular screening tests to help prevent colon cancer by determining and eliminating polyps before they start to turn into cancer.