Celiac disease is sometimes known as sprue, Celiac sprue, non-tropical sprue, or gluten-sensitive enteropathy. It is an autoimmune disorder, which is where the body attacks itself because it is responding to what it considers an outside invader (gluten).
Celiac disease is a form of gluten intolerance. But with Celiac disease, there is damage to the small intestine. The antibodies attack the gluten (and in addition, the small intestine). And the villi are damaged, sometimes to the point of the intestinal wall becoming smooth.
(The villa are the small, wormlike projections in the small intestine that increase the surface area to absorb nutrients.)