Celiac disease (also called sprue, nontropical sprue, celiac sprue, and gluten sensitive enteropathy) occurs when the body reacts abnormally to gluten, a protein found in wheat, rye, barley, and oats. Gluten causes an inflammatory response in the small intestine, which damages the tissues and results in impaired ability to absorb nutrients from foods. The inflammation and malabsorption create wide-ranging problems in many systems of the body.

The exact cause of celiac disease is not clearly understood, but it is known that both heredity and the immune system play a part. When food containing gluten reaches the small intestine, the immune system begins to attack a substance called gliadin, which is found in the gluten. The resulting inflammation causes damage to the delicate finger-like structures in the small intestine, called villi, where food absorption actually takes place.

The most commonly recognized symptoms of celiac disease relate to...