Have you looked into Mast cell activation syndrome (disease)? After 2 years of no-diagnoses for my grandson's everyday nausea and abdominal pain, (he had every medical procedure in the book) our research found MCAS. We have hundreds of mast cells in our body, which are there to help control reactions to different things. Sometimes, they run amok and cause problems rather than fixing them. We watched a video done by Ilana Jacqueline who suggested a MRT blood test for food sensitivity. My grandson went through food allergy testing, but nothing showed up. This MRT test (pricey) determined he was very sensitive to turkey...of all things! He had turkey/cheese sandwiches every day during his first 2 years of high school! There were several other things (food as well as chemicals) that were causing triggers in his body. Having had type 1 diabetes since he was 10 months old, his parents thoughtfully gave him mostly zero carb foods and beverages. Artificial sweeteners like aspartame are in almost everything he has been consuming all those years. Read about aspartame....it turns into formaldehyde once it warms up in your stomach. How gross is that? Anyway, since he has stopped drinking diet sodas, his daily nausea and pain have stopped. We also watch the other things that he is sensitive to, such as corn. Corn is in many products, so it's pretty difficult. He is also sensitive to polysor80, which is an emulsifier used to make things creamy, such as ice cream, salad dressings, etc. There are a bunch of others that we are trying to eliminate from his diet, but I have to say, that we believe the aspartame has been the culprit. Just a suggestion. Hope you can get some relief. We understand your frustration. We had to do our own research to get the doctors to authorize blood tests and procedures, just to rule out so many other possible diseases.