I would suggest to stop carbonated sodas, caffeine,
alcohol, citrus, dairy, tomatoes, peppers
and potatoes
and gluten for 1 week. Then reintroduce only gluten products for a day or two and see how you feel. Continue your PPI during this time. If your symptoms come back it is gluten. If the symptoms do not come back then reintroduce another food. Keep a food diary on your intake and symptoms. If it is a food intolerance the symptoms may not start immediately after eating.