Celiac disease is an immune-mediated enteropathy characterized by injury to the small bowel triggered by the ingestion of gluten (a protein found in wheat, barley, and rye) in genetically susceptible individuals. Symptoms of celiac disease may develop any time after gluten-containing foods are introduced into the diet, usually after 6-9 months of age. Prevalence in the general public is 1:100. The approximate prevalence in first degree relatives is 1:20 and second-degree relatives is 1:40.