airtas - Yes, diarrhea is a common side effect of BuSpar (buspirone). It is usually self-limiting and goes away within a week or two of starting the medication. BuSpar acts upon serotonin recptors in the brain to reduce anxiety. Unfortunately, there are also serotonin receptors in the intestines as well. Your body will adjust itself to the increase in activity of the serotonin nerves and the diarrhea will abate. Hang in there.

I hope that this is of some help. - Cam