It sounds like it could be irritable bowel syndrome, i had these symptoms and i went to the doctor and was diagnosed with ibs, it could also be a wheat?gluten intolerance, you could try leaving wheat/gluten out of your diet and see what happens, i know how you feel it is extremely painful.
I have been having the same pains i have a docs appt later this week if i find out what it is ill let you know so you can be checked for it to