Cool, if you haven't been following a diet recommended for GERD and made lifestyle changes, make sure to try those. Many times meds alone may not be able to control GERD. Also have your gallbladder checked. In some cases the symptoms of GERD and gallbladder issues can be very similar.
Acute Gastroenteritis means "Your stomache hurt really bad, suddenly". You have WAY more serious issues than that! See a gastro doctor ASAP. Bile should NEVER, EVER leave your mouth. Get some keto strips (to pee on) at the pharmacy desk (about $6.00 for 50) and use them REGULARLY. Twice a day will do, until you are well. They indicate ketones in your urine that accumulate when you are dehydrated. BUY PEDIALYTE SINGLE PACKS in the baby section at a grocery store or Walmart type store. They have 8 times the potassium than Gatorade type drinks that contain salt and sugar in large amounts that can further dehydrate you and elevate your sugar levels. The SINGLE PACKS taste great, (not the liquids!!!!!) and they are portable. Use one to two in your WATER if needed and recheck urine after an hour. You may have pancreatitis from a gallbladder problem, (even if it's been removed). DO NOT DELAY, MAKE AN APPT TODAY!