I have alot of problems intermittantly with huge amounts of upper GI pressure, gas, belching, and feeling like a small animal is living in my chest. I haven't been able to decide if it's from my GERD or my IBS. I have a glass of coke every morning, and it doesn't seem to bother me. But if I'm having a flare of my IBS/GERD, even though the coke doesn't bother me, if I take one Exedrine (that has 65mg of caffeine in it), it makes my symptoms alot worse later that day. Just curious how caffeine affects your IBS, and can you use it sometimes, but not others? Thanks.