POST OP - HORRIBLE GAS PAIN ?

I had open RNY revision surgery on 4/8/09.  I am still on the full liquid diet.  Yesterday I decided to add cream of celery soup (just a few ounces) and about 2 oz. of V-8 juice.  Since then I've had incredible pain on the left side of my mid back, and under my rib cage on the right side.  It hurt so bad last night I couldn't sit up.  The pain seems to have dissipated somewhat, but is still lurking.  I've taken Mylanta and Gas-X but it still has not totally gone away.  Any input regarding this issue would be greatly appreciated. 

lalala2