Rebound is generally the period after you stop acid suppressors. There are some theories about whether the stomach starts over-producing acid once you stop, but I have also heard that gastrin secretion in the stomach increases with the use of PPIs to compensate for the lack of acid. Once acid comes back the gastrin levels are still elevated and then become active which attacks the stomach lining. It takes a while for gastrin levels to reduce back to normal which is why its recommended to reduce PPIs gradually over time to get accustomed to the increased acidity.

Rebound generally takes 1-2 weeks since stopping PPIs to reach its peak. Zantac doesn't generally have rebound of much severity as acid levels aren't reduced as much as with a PPI, but you will probably notice very quickly after discontinuation as it doesn't stay in the system long.

Thanks Andy. My doctor told me I could stay on Zantac as long as I wanted. Things got much better, but every few days I feel bad again. And I'm getting palpitations again. They finally stopped all together, but now I feel them at least once a day. Do you think the Zantac could cause that?

I also have to say that my IBS and the Fibromyalgia have both been just attacking and attacking lately. All of which can cause palps. All systems are DOWN and bring me down with them.

What kind of problems and difficulties you are facing in IBS