The Human Body


Feces, also stool, excreta, or residual waste materials, evacuated from the bowels. Through peristalsis (involuntary intestinal contractions) and digestion, partly digested food begins to assume the aspects of feces when it passes from the small intestine to the large intestine. In a healthy digestive system, feces consist of undigested and indigestible food products such as mucous secretions and cellulose; traces of intestinal juices from the liver, the pancreas, and other digestive glands; undestroyed enzymes; leucocytes; epithelial cells; cellular debris from the intestinal walls; fat globules; nitrogenous protein products; mineral salts; water; and large numbers of bacteria.