I had reflux esophogitis. i was on ppi in am and pepcid in pm. once i start tapering i am told to stop the pepcid first. how do i know the difference between just acid rebound and gerd that is damaging my esophogus again?

Any symptoms that recur after you begin tapering medications should be reported to your GI doctor who knows you best to determine what is expected and what is more worrisome. You likely won’t be able to tell the difference symptom-wise but your doctor will know which symptoms, especially in terms of degree of discomfort, is safe and expected. Hopefully, you won’t experience any symptom recurrence.