Chronic gluten intolerance (celiac disease) is an inherited disease caused by eating foods made from wheat, rye and barley. The gluten in the protein in these cereals causes damage to the lining of the small intestinal mucosa, which results in impaired nutrient absorption and nutrient deficiency. Typical symptoms are abdominal pain, chronic diarrhea, nausea, vomiting and emaciation. The treatment is a lifetime strictly gluten-free diet.