The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.

This abdominal x-ray shows a stomach filled with fluid and a swollen (distended) small bowel, caused by a blockage (obstruction) in the intestines. A solution containing a dye (barium) that is visible on x-rays was swallowed by the patient (upper GI series).

This abdominal x-ray shows thickening of the bowel wall and swelling (distention) caused by a blockage (obstruction) in the intestines. A solution containing a dye (barium), which is visible on X-ray, was swallowed by the patient (the procedure is known as an upper GI series).

A series of normal coordinated, rhythmic muscle contractions, that occurs automatically to move food through the digestive tract is called peristalsis.