What's wrong with my stomach?

For the past couple years, I have been having this horrible abdominal pains in my lower left hand side. These past few months I have decided to do something about it. I have learned that I don't have any food allergies, I have a normal WBC count, no ulcer bacteria, no inflammation, and nothing wrong with my TSH levels. As a nursing student, I have been looking into what this could be, and I have no idea. The doctors are calling this Irritable Bowel Syndrome. (I have lots of bowel movements each day, my abdominal pains, and lots of gas and burps). Does this sound like IBS? (one of my friends have it but with opposite symptoms..) Also, I have been given a medicine called "Levsinex Timecaps".. to help "relax" my stomach.. what does it actually do to my GI tract? Thanks for you time..