Celiac disease is an autoimmune response (your body releases antibodies to wheat, like it was a pathogen).
My mother was recently diagnosed with having Redactive Celiac disease, which is pretty much the worst sort - the problem is, doctors had been treating her for IBS for 10 years before they found out! Apparently the symptoms of IBS/Celiac are very similar & as a result Celiac is very difficult to diagnose (or that's the excuse they gave).
The reason I bring this up is HotToddy, have you been tested for IBS?