Weather Changes/Severe Stomach Pain/Rotten Egg Burps

Whenever the barometic pressure changes drastically, I get severely sick.
Symptons include:
--severe stomach pain similar to heartburn
--elevated liver enzymes
--nausea
--vomiting (makes it feel better for about 10-15 minutes)
--horrible rotten egg burps (enough to clear the room!)
--diarreha

Things that help:
--heating pad on stomach
--Zantac 150
--Prilosec
--vast quantities of Pepto Bismal
--Peppermint pills with enteric coatins

Pain is so severe I've gone to the ER only to get every test under the sun but all negative except elevated liver enzymes.

When I'm well, all is ok. Liver is normal.

I can tell when a storm is brewing because I'll slowly feel stomach discomfort, then it builds to unbearable levels. It lasts 5-10 days, then I'll be well again...as long as the weather stays calm.

Ideas?