The problem with PPI's -- any PPI, whether Nexium, Aciphex, Prilosec, or Prevacid (which I'm currently on, 30mg/2xday for GERD) -- is that once you go off of it, the stomach goes into overdrive with creating acid. Unfortunately, the rule of thumb there is that it'll do that for about as long as you were taking it. (If you were taking it for a month, then it'll happen for a month after.