After a fairly heavy (but not extremely heavy) meal incuding a cocktail and some wine (typical, in my case), I was awakened at around 2 AM by experiencing, for the first time in many years, serious abdominal pain.   Pain was relieved by drinking several small glasses of skim milk and walking around.   Pain seems tp be  lessened by eating something (and more milk).   This situation has persisted all day (around 15 hours, by now).  

I am worried because this kind of pain is so unusual for me.   My doctor thinks I may have IBS (but he is not sure); my "IBS" symptoms have always been diarrhea (and occasional constipation), as well as gas, but never pain before.   Stomach ulcers, stomach cancer, and pancreatitis run in my famiy; I myself had gastritis many years ago, characterized by violent vomiting and intense abdominal pain.   

I am under considerable stress these days, but that's nothing new. What is going on?