Digestive system. Computer artwork showing a healthy human digestive system, superimposed on the outline of a human figure. At top is the bean- shaped stomach, in which swallowed food is stored and digested by acidic gastric juices. The food then enters the small intestine through a C-shaped duodenum. The small intestine is the longest region of the digestive system, seen as the thin coiled tube in the abdomen. Here, digested food is absorbed into the blood. Food residue then passes into the large intestine or colon, a wide circular tract in which excess water is absorbed. Faeces is stored in the rectum (lower frame). The appendix is the finger-like structure (at lower left).