Hi! You mentioned gurgling in your stomach. At one time, I had a lactose intolerance and the gurgling would be my warning that diarrhea was coming on, and i would have enough time to get to a bathroom in time. The other problems you mentioned, lightheadedness and chest pain may be due to hiatal hernia. You would need to take a test at your local hospital to get a diagnosis of this. I do have hh and have the same symptoms you mention. There is medication for this, although I don't take it. I take many other meds as I also have fms. Hope I have helped you.