Celiac disease is a condition in which a person is not able to digest gluten, a protein found in wheat, barley & rye. Gluten is also present in other food products like soy sauce, salad dressings, vitamins & candies. If you suffer or have a family history of Celiac disease, your immune system reacts when you eat gluten. Symptoms include diarrhea, constipation, bloating, fatigue, weight loss & malabsorption. Children can show delayed growth. This test detects IgA type of tTG antibody to diagnose Celiac disease. This antibody predominates if you suffer from Celiac disease.