I am a retired Registered Dietitian in Canada and have had many Celiac patients while working on the Gastroenterology ward and outpatient clinic. It is an unfortunate diagnosis but one that can be successfully treated with due diligence. But it is a serious disease and I would encourage you to read up on the long term outcomes. Now, I have been retired for 16 years so I am sure things have changed over that period of time.
My suggestion would be to definitely seek out a Pediatric Registered Dietitian who has experience with this disease. Not sure where you are but your physician's office would be a good starting point especially if it was a Gastroenterologist who you saw or the American/Canadian Dietetic Association may have a listing of Dietitians in your area with appropriate experience or the local hospital. Be sure to use a 'Registered Dietitian" because they will be appraised of uptodate information about the disease and dietary management such as knowing all the ingredients that should be avoided. And seeing your son is only 3 years old it is very important to get him on the correct diet. You will need help! It would be a great idea if your family adopt a gluten free diet at home. It would help your son to accept the diet and learn that it can be good tasting. Who knows, you may be celiac also seeing you feel better after trying the diet for a few days. We used to get 50 year olds who were diagnosed after years of suffering.
In Canada we have the Celiac Association and they were a wonderful group who held information and support sessions for new people and complied information about which local restaurants are good, etc. They had a good product catalogue showing which products were gluten free.....a quick reference for when you are just starting out. They also had a library of cookbooks or could recommend such books.
When I was practicing my understanding was that is very important to be totally gluten free. So x-cross contamination in the kitchen is a real issue. Separate cupboards, toasters, cutting boards, etc. This is why dinning out is a big problem..x-contamination. If the gut is exposed to gluten it gets damaged and has to regrow the damaged cells. During the time of damage, nutrients don't get absorbed properly and the gut's integrity is compromised. Some people if they are continually exposed to small amounts of gluten do not respond when a totally gluten free diet is provided.
I am sure there are a whole lot of snake oil salespeople out there who would be willing to take your money for advice or to offer a remedy. My advice is to stick with the health professionals. They will provide you with loads of good, reliable resources.
Sorry I don't have any recipes except learn to make a really good risotto and polenta
