Hi Hunnypie:
First, sorry for your discomfort. I always like to preface everything I write with the disclaimer that I am not a medical doctor or medically trained. All I can give you is my educated opinion from personal experience and a lot of reading.
I always worry when doctors throw medications at symptoms without investigating the underlying cause a bit more. I too suffer from acid reflux but do not have all the other symptoms, which suggests to me that you have something else going on besides or along with the reflux. I don't mean something horribly serious or anything like that, but you could also suffer from irritable bowel syndrome or Crohn's Disease. You could also be suffering from a glutten or lactose intolerance. My concern is that physicians know these are not death-threatening illnesses or disorders and do not have the time to investigate and explore these symptoms or suggest dietary changes that may help a patient. Instead, they throw these very potent medications at us. I have had that experience with more than one physician over the past five years.
You can try experimenting with your diet to see if changes in diet help the diahrrea and nausea. Eliminate all dairy from your diet for a week and see how you feel. Then, slowly reintroduce dairy but eliminate wheat products as much as you possibly can to test for the glutten intolerance. FooRAB such as coffee and alcohol are very irritating to the stomach and intestines. Try eliminating those to see how you feel. Try to lower the amount of carbs you consume.
I am not allergic to wheat (as far as I can tell), but I don't digest milk or milk products very well. Therefore, I now drink almond milk. It is a time consuming process to go through all the fooRAB one can and cannot eat but worth the effort. I feel we must try to take control of our health with our physicians' input and help.
You may wish to seek a second opinion if your doctor only continues to throw PPI's at you and does not order any diagnostic testing. If acid reflux was the only problem, the PPI would have likely controlled that symptom. The fact that you have other symptoms suggest to me that a) you either have a bad reaction to the PPI's or b) something else (other disorder or disease) is going on along with the reflux.
Hope these thougths help and that you feel better soon.
Rose