I had a triple bypass in 2007.I have been having pains ever since.Best safe than sorry.I agree with the above comments. Go to the ER next time it happens.
You should notify your cardiologist and surgeon about your symptoms. The next time you have an episode you should go to the ER. It could be related to your surgery or your heart or it could be related to your G.I. system but without further evaluation, no one knows.
Keep us informed on how you're doing.