I would recommend a homeopathic doctor, then. Traditional doctors don't understand this as much. He can probably connect with one via video chat.

In my experience, my body works on a tolerance level.. each "illegal" food having its own limit. For example, if I consume one offending food, I may notice symptoms instantly. Yet with other offending foods, it could take several days or uses for the symptoms to showcase itself.

I'd suggest an elimination diet, too, to filter out what foods is causing what. The idea is to eliminate most common food allergens (dairy, grains, soy, corn, sugars, etc) for two weeks. Then, one by one, slowly reintroduce each item in large quantities. You'll notice a reaction between 4min to 4days (so choose one item per week). It's a lot of work but so is the life you're both dealing with right now.

Another thing to consider is heavy-metals detox. I've used Advanced TRS and flatlined my toxicity levels to a near 0 (and I mean 0.342, as an example) for all of the metals on the panel. Just something to think about.