I agree with Molleyrae, but understand your frustration. Is it after eating a certain food, or type of food? i wish i could help you. Gas pain can be very painful. Good luck.
shinty
In my opinion when you say that it happens occasionally after eating, it sounds gas related. A Gastroenterologist can help you there.
I don't know, but it sounds somewhat similiar to this thread.
http://www.medhelp.org/posts/Pain-Management/pain/show/1953906
If it isn't Im sure someone with a similiar problem might be able to help. Though going to the doctors again may be the best bet.