Hi Melodie-
Glad you at least found one common denominator with his symtoms (people food). One thing to consider about your idea that a rotational diet will fix the issue because he will do well on a food for a short time and then have symptoms again…a rotational diet could simply mask the symptoms and not let you know if he is actually better or not. The goal should be to know that there is a food he CAN eat long term with no symptoms.
It may still be wise to pay the money to see an internal medicine specialist and have en endoscope and biopsies done of his GI tract.
