The colon, or large intestine, is about 5 feet long in humans. The large intestine is the last segment of the digestive system, which is 30 feet in total length.
The small intestine, at 20 feet in length, is the longest section of the digestive system. Most of the digestion and absorption of nutrients occurs in the small intestine. Any nutrients left in partially digested food after going through the small intestine are absorbed in the large intestine. The large intestine also absorbs water to convert the liquid digested food into solid stool before its final excretion from the body.