If you have fructose malabsorption, PPI's can cause acid reflux. At least Prilosec can because it has sugar(s) in it. You can look up any drug in Daily Med to see a copy of the package insert including side effects and so-called "inactive" ingredients. I made a posting in the Fructose Malabsorption discussion group about going to a list of different names for sugars and then looking up drugs in Daily Med.