Hi Katherine -
Do you have a good list of foods that you know always trigger your reflux? After keeping a good food log, doing challenge testing of the ingredients, consulting with my allergist, I googled my list, a few foods or ingredients at a time, with the words "food allergies" and "food intolerances," and came up with what tied them together. In my case it was sulfites. I can eat lots of so-called GERD triggers like tomato sauce if it's home made.
For several years I was able to pretty much not have active reflux by avoiding my sensitivities - until I got into a bad wreck that pushed my stomach into my chest. Then it was surgery.
I hope you are having regular checks with your gastro. You might want to make another appointment after he gets the results from the next test, a couple of weeks. Make sure you ask for the results to be sent to him!
I find it helpful to ask for a copy of all test results and some disks of pictures of tests for myself. I keep finding more doctors I need to have them for, and I make copies for them. Reading the results gives me more information than just having the doc summarize it in simple language.