How long is a human colon?

The normal human colon is about 5 feet long. Its main purpose is to hold and dry out waste material produced by digestion. The gut flora in the colon break down materials that remain unabsorbed.

The colon has four layers of tissue, all of which help waste matter pass easily through the lower gastrointestinal tract. These tissues either secrete lubrication or are muscles that cause the colon to contract and push the material forward. After water is removed and the bacteria in the gut ferment previously unabsorbed materials, this fecal matter is stored in the rectum and passed out of the body.