My daughter has celiac which we caught early (concomitant with T1D) although she is not as hypersensitive as some people I have met, it is still crucial to avoid all gluten as even without overt symptoms it effects overall growth and nutrition.
But some of our friends are so sensitive that even minuscule levels of gluten exposure cause intense distress within an hour.
You have a “wasting” disease which is clearly non-contagious. Is it not obvious to test various strict diets? I guess in advanced cases it takes months of a gluten-free diet for the intestine to start healing (years for full recovery) so short-term test diets would not have led to full recovery, but even if you just experiment with carb-free that would reduce gluten so much I would think someone would have caught onto this sooner!