Celiac disease causes inflammation in the small intestine and damage in the lining. This prevents the body from properly absorbing the nutrients in food. The damage to the lining of the intestine comes from a reaction to eating gluten, which is found in wheat, rye, barley, and possibly oats, and in food made from these ingredients. The inability to absorb nutrients can lead to weight loss, fatigue, malnourishment, and other health problems. Gluten may be found in many foods, especially processed foods and baked goods. Breads, cakes, desserts, alcoholic beverages (except wine), cereals, and pastas may all contain gluten. Eating a gluten-free diet heals the intestines and prevents further damage.