In the human body, the small intestine is located within the central and lower abdominal area. It stretches from the stomach to the large intestine, coiling around several times to fit. Food travels from the stomach directly into the small intestine.
Long and narrow, the human small intestine measures about 20 feet in length and approximately an inch in diameter, though actual size depends on the person's age and body size. Three sections make up the organ: the duodenum, the jejunum and the ileum. The break down and absorption of nutrients from consumed food takes place in the small intestine. Folds located inside the small intestine further increase available surface area of the organ, up to about 250 square meters.