My son is coeliac, and so when we started him a t school aged 5 we carefully and clearly informed the Principal that he mustn't eat the "breakfast" snack of bread in the mornings and that he would bring his own in his bag. She agreed with this and assured us that his teacher, who we could not see then, would be informed.
All bags had to be left on hooks in the corridor outside classroom.
On the first morning I began to check with his teacher that she was aware of this arrangement; she responded as if she knew everything necessary before I could say much.
When I came to pick my son up at lunchtime his snack was still in his bag. He had refused the bread offered amongst the children, but being virtually mute at school, ( his teacher said he almost never said a word all the time he was at school, but she didn't see this as a problem, which it wasn't for her of course, his being nice and quiet.) with language difficulties generally, he had not been able to ask permission to get his bag. His teacher knew nothing about it.
When I confronted the Principal about this breakdown in communication, she seemed blithely unconcerned, and did not seem to see any need to apologise. So I had a screaming meltdown right there in the corridor in front of dozens of parents and children.
My child's difference ( allergy to wheat) had completely and utterly not been taken into account. We didn't even know about AS at that point.
