Coeliac disease - I understand from other friends who have been diagnosed with this that it's tricky but OK to deal with being gluten-free forever. My MIL has been diagnosed with this a year or so ago. Out of the blue she just announced she cannot have gluten any longer, and has Coeliac disease.
Just a bit of history - my opinion is that she seeks attention in all situations. My husband and my wedding - she demanded my private list of 'to-do' items including such things as 'wax bikini line', and when I did not give it to her she threatened not to come to the wedding until I apologised. Now, she may have CD and we always get in lots of gluten-free foods when they visit. She always asks in restaurants for the GF options. (and bemoans how poor they are). But most times we see her she will eat something containing gluten, like a regular biscuit or a bit of batter off fish and chips my FIL is eating. Can you just have a minor allergy to gluten? But she does insist it's Coeliac disease.