What Causes Occasional Pain At And Around The Rib Cage?

I have a SEVERE, occasional pain, about 3 to 4 times a week, only when I am sleeping, waking me up. I sleep on my right side and the pain is located just at or around the bottom of my rib cage. I cannot associate it with diet changes or modifications and if I can unparalyze myself from the pain and turn over it will go away. HELP!