A digestive research center changed my life. My gluten-induced symptoms (inflammation, joint pain, diarrhea, etc) is linked to something with my gut bacteria. If I take a certain antibiotic that targets the digestive tract, I can eat anything for 9 months including gluten, without problems. After about 9 months, I can no longer eat gluten. And then about a year after that, I can't eat corn. This has repeated 4 times. I always test negative for celiac and sibo. Side note: The doc told me some patients are cured by antiparasitic meds rather than antibiotic.
The doc is now using wellbutrin to change my brain-gut communication and amazingly it cured my corn intolerance and is improving my reaction to gluten, but not yet to the point where I want to eat it. I have 4 more months to go, so this may improve.
Lastly, I know 2 people whose thyroid issues masquerade as gluten intolerance. Consider a "comprehensive thyroid panel"