What Causes Abdominal Pain And Cramping?

I experience very painful crampy feeling in left and right abdomen when sittiing after eating and sometimes even on an empty stomach with gas in my intestinal tract ~ its like a balloon being blown up in my abdomen ~ its so excruciating when it happens and I never can tell how long it is going to last ~ I have to stand up and try to stretch myself to get rid of it ~ Can you help me?