I was taking nortriptyline 25mg before bed, and it worked great! I was able to eat in the morning without running for the bathroom. But after I was on it for two weeks, I started having chest pain, rapid heart rate, and nausea about a half hour after I took it. My doctor told me to stop taking it, so now my IBS is out of control again.Has anyone else had these side effects? Perhaps I wouldn't have them if I took the nortriptyline with dinner? Or maybe I could find a lower dose?