Animation of polyps on the inner wall of the large intestine. Polyps are abnormal growths of tissue on a mucous membrane. Many polyps in the colon produce no symptons, although there is a risk that the benign colon polyps can turn cancerous. The two polyps on the foreground grow directly from the wall, and are called sessile. The other one is attached via a narrow stalk, and is said to be pedunculated.