Check out this other thread where we vented out about our stomach issues:
http://neurotalk.psychcentral.com/thread164430-2.html
Amitryptline affected my stomach and made me very hard to quit and still suffer from its effects. Some of us has sensitive stomachs. SSRIs/Tricyclics affects the serotonin level in the stomach too.
Now I deal with stomach issues (besides PCS) all day/everyday.