Thanks queen for your reply.
I'm so glad you got the tests done for coeliac disease and now at least you know to take gluten away. The GPs are so bad at even thinking about it, it's unbelievable. Did you ever try taking dairy away (including all the hidden lactose in biscuits/processed foods) and see how she goes? Does she have diarrhea?
My DD is 6.5. She was diagnosed with severe IgE allergies to cow's milk protein (anaphylactic shock) at 6 months, the same tests found her allergic to eggs, and very slightly to gluten and some nuts. They were all going through the breastmilk and causing bad eczema. 2 weeks after stopping she was thriving and had beautiful skin. That was before autism started... According to the same blood/prick tests, the allergies have now reduced and we're supposed to give her foods with dairy and gluten, even though the docs said she might have become lactose intolerant because she was never exposed to dairy as a baby, and never developed the lactase enzyme. I'm lactose intolerant myself and it's not nice, so I never wanted to "expose" her to that.
Her gluten sensitivity isn't as clear as coeliac but she's much better without it, so we keep the gluten out.
Fully understand it's hard work trying to explain to your younger DD why she can't have the same treats as her older sister!
Also fully agree that it's easier to raise a child with autism who doesn't have these gut issues, it's like having 2 disabilities and the usual ASD advice just doesn't work due to the poor child feeling ill all of the time...
When you feel that way how can you possibly be compliant and cooperative with school and OT exercises?
For what it's worth, my DD became extremely picky when she was 4-5, it seems like everything was causing tummy pains. We did various food eliminations, probably too much, which helped her digest better but made her even pickier as she never wanted to re-try previous foods (especially veg!).
We worked with a naturopath specialised with ASD, used lots of probiotics and supplements to heal her gut issues and it massively improved.
Then I used a method for extremely picky eaters to teach her to trust food again (we were at the point that she skipped ALL meals for several days in a row, literally survived on little bites of crackers and bananas, it was awful). It worked really well even though she's still reluctant with many things, but I can't complain. Here's the book link if it can help.