Celiac disease has a wide range of symptoms so it can be difficult to diagnose. If you have gastrointestinal distress that persists or recurs, or if you have any symptoms of nutrient deficiencies, you could have celiac disease. In order for the doctor to make a diagnosis, he or she must rule out other diseases that can have similar symptoms as celiac disease. Some of these include: irritable bowel syndrome, gastric ulcers, Crohn’s disease, parasite infections, skin disorders, iron-deficiency anemia, diverticulitis, intestinal infections, and chronic fatigue syndrome.

If you have symptoms consistent with celiac disease, a blood test can help determine if you have the disease or not. The test determines the levels of certain antibodies in the blood that are directed against your own body tissues (autoantibodies). Specifically, three autoantibodies called anti-tissue transglutaminase antibodies (tTGA), anti-endomysium antibodies (AEA) and anti-gliadin antibodies tend to be present at higher than normal levels in the blood of people with celiac disease. These antibodies may be made by the body in an attempt to rid itself of gluten but they end up attacking cells of the small intestine instead. While this test alone is not enough to diagnose the disease, negative results can eliminate celiac disease as a possibility.

If you do have high levels of these antibodies in your blood, the doctor will likely want to do a biopsy of the small intestine to confirm the diagnosis. In this procedure, a tube with a small camera called an endoscope is placed down the throat and threaded through the stomach to the small intestine. When there, a tiny piece of the small intestine is removed using instruments passed through the endoscope. The piece is then examined for signs of damage to the villi that is characteristic of celiac disease.