There is some confusing terminology being used in reference to gluten intolerance. Sometimes you will find Gluten intolerance, Celiac disease, wheat allergy, and NCGS (non-celiac gluten sensitivity). In fact, these terms are different diagnoses altogether.
CD is an inherited autoimmune disease in which the lining of the small intestine is damaged from eating gluten and other proteins found in wheat, barley, rye, and possibly oats. With celiac disease the villi, small hairs inside the small intestine responsible for absorbing minerals and nutrients, flatten essentially making it extremely hard to do their job. Celiac disease occurs when proteins in gluten trigger your immune system to over-react with strong and unusual antibodies, wearing down the villi in the intestine. Only a blood test can definitively diagnose CD.
Wheat intolerance or allergy is different from Celiac disease or gluten intolerance. With wheat allergy, there is an immediate histamine response to wheat. The response would be similar to someone having a reaction to cats if they are allergic. There would be an immediate reaction after a single exposure. A wheat allergy can manifest itself in many different ways from hives to stomach pains. Wheat allergy is a response of white blood cells called basophiles and mast cells to immunoglobulin E. There is a misconception when it comes to adults and wheat allergy. Yes, an adult can develop a new food allergy. Most adults think that they know their bodies and their sensitivities, but the body changes over time.
If you have all the symptoms that point to CD, your physician will give you a simple blood test. If the results are positive, then you have celiac disease. If they are negative, then you have non-celiac gluten sensitivity. Adults with anemia, infertility or osteoporosis should consider getting checked. NCGS is more difficult to pinpoint than the Celiac disease or wheat allergy. The symptoms will be systemic and have a slow on-set.