Gas Pains in Stomach and Lower Back

For the past 2 weeks I have been having problems expelling gas through  burping or farting.  My stomach is bloated and I'm experiencing pain in my lower back as well.  I have tried Phazyme, and today I tried  baking soda and water, and that seemed to help some. Will I always have to use baking soda to get a little relief or is there something else I can try?  I drink alot of Powerade and apple juice and eat alot of watermelon.  Could those foods be causing the gas pains?   I'm miserable.  I also have this feeling as if something is always stuck in my throat.  I don't think I've done anything wrong.  I'm 11 weeks post-op.  What could the problem be?  I desperately need your help!  Andrea

I just recently had the same problem. My Dr. recommended Milk of Mag.