Great question Renee! I have read studies here and there stating that it is an autoimmune disorder. If it's on the internet, then it has to be true right??? Haha, sorry, I couldn't resist Seriously though, Bram is correct in the fact that so many of us do have other autoimmune issues. It has to be related. I tested negative for celiac, but am definitely gluten intolerant. I also have malabsorption problems, gastroparesis, severe deficiencies in vitamins D, B12 and potassium, interstitial cystitis and allergies galore.