I suggest talking to a nutritionist – they should be able to give you resources.

I wonder if you found something to help your situation? I’d love an update

I do not have recipes but hats off to you. My son vomits everything right after the meal. sometimes i feel like i am done i can’t handle anymore. So good on you

I really applaud parents that are required to go the extra mile for their kids, and it just becomes seamless routine.

I myself recently had to do low residue diet after a flare up of diverticulitus. I came up with a cheddar potato soup that we served with white bread.
A bunch of potatoes (peeled and chopped), one brown onion, garlic, cover with vegetable or chicken stock, boil the potatoes. Drain when cooked. Separate the potatoes 50/50. Puree half. Add thickened cream (depending on how thick you like your soup), half a cup of sour cream, and a cup of grated cheese – blend again. Combine with the chunks of left over potato (this is optional, I prefer a chunkier soup), you can puree the lot if you prefer.
Top with cheese, green onion, chives and/or bacon bits.

There might also be some useful resources/books to research from the library on this topic.

A dietician would be a good resource for information on your child’s dietary needs.

I can’t help but maybe look for some facebook groups for the condition, or similar ones, that may help each other.

You might find some idea’s here
https://www.webmd.com/ibd-crohns-disease/crohns-disease/low-residue-diet-foods