What Causes Pain On Right Side Of Abdomen On Intake Of Food?

I have severe pain in my left an right side 20, to 30 minutes after I eat. I have had over 50 tests, Dr.s say they can not find any thing wrong with me, would you know why it hurts too eat an or drink anything, now even water causes severe Pain.
all they can do for me, is give me Morphine 13 hour IV push drip, an I also take 5mgs as a prn, 3 times a day too stay out of hospitals. I don't want too become addicted too pain killers. Would you have an ideas as to wat this pain is coming from, an wat else I can do about it. Thanks in advance