^ This.

• There’s coeliac which is the most easily identifiable,
• a generalised gluten allergy, which - last time i checked - needs you to stay off/stay on gluten consumption for a week leading up to a blood test
• allergy to one specific grain like wheat, but not all gluten.
• and there are people who just have really bad digestive issues but have found that going gluten free helps.

We should have more sympathy for people who have to grapple with this shitty, under-researched allergy