The colon/rectal is also known as the large bowel or large intestine. It is an organ that is part of the digestive system (also called the digestive tract) in the human body. The colon helps remove water, salt, and some nutrients forming stool from the body and is lined with muscles that squeeze its contents along. Different diseases can affect the colon like Colitis, Diverticulosis, Colon bleeding, and Diverticulitis.