Celiac disease is a chronic condition mainly affecting the small intestine. It is a permanent sensitivity to gluten, a protein from wheat, rye, and barley. In affected individuals, eating food containing gluten leads to damage to the finger-like projections, or villi, lining the small intestine. Other names include celiac sprue and gluten-sensitive enteropathy. Celiac disease is considered an auto-immune disorder, in which the body attacks itself.