What Could Cause Lower Stomach Pain?

I'm having lower stomach pains on the right side, no fever, no vomiting. Not been very hungry but still eating small amounts. The pains come and go, mostly just uncomfortable but sometimes the pain levels rapidly go up to severe (taking my breath away, not able to move for about 30 seconds). I doubt appendicitis, but at this point not sure what else this could be.
Had gallbladder out 11/4/2011, kidney stones/hospitilization required, stent placed then removed 60 days later 5/2009, kidney stone/hospitilzation required 8/2010. Left side 11 centimeter ovarian cyst surg. removed 3/2009.