The small intestine is a winding, tightly folded tube about 6 m (20 ft) long in adults. It is connected to the stomach on the top end and to the large intestine (colon) on the bottom end.
Most of the food a person consumes is digested and absorbed in the small intestine. The lining of the small intestine has tiny finger-shaped raised tissues (villi). These raised tissues greatly increase the surface area of the intestine, which absorbs calories and nutrients from food.
Medical Review:E. Gregory Thompson, MD - Internal Medicine & Brian O'Brien, MD, FRCPC - Internal Medicine & Adam Husney, MD - Family Medicine & Peter J. Kahrilas, MD - Gastroenterology