Celiac disease is a genetic autoimmune disorder where eating gluten causes damage to the small intestine. Gluten is found in wheat, barley, and rye. It affects about 1 in 133 people. The only treatment is a lifelong gluten-free diet to avoid damage to the small intestine. Common symptoms include weight loss, stomach cramps, and malnutrition. While there is no cure, following a strict gluten-free diet can help manage the disease.