Hi
Totally appropriate to post this here as EE and reflux often exist together. Has your son been treated/tested at all for gastric reflux as some of what you describe could be that? The gastroscopy will show this up anyway if it is causing damage. I would go ahead and get it done, and then you know.
There was a good article on Medscape recently on EE but you need to join to view it. I can email it to you if you pm me your email address. Or was it you who replied to the message over at Treasures?
My eight year old reacts to dairy and gluten that we know of, but can now tolerate some soy. She had surgery for her gastric reflux at age eight years because it was obvious she was refluxing significant volumes even though the acidity was well controlled. We did discuss EE at the time but decided to leave investigating this until later. The surgery has helped heaps but she does still have some symptoms and a lot of these appear to be allergic. I also have similar symptoms with dairy, gluten, tomato and pork.