Re: Gnawing in stomach, is it IBS?
Ay other tests? Any other family problems that may be a factor to other causes (diabetes, etc) Did they check on your gallbladder with ultrasound or hidascan? If not / either way you can try changing your diet up a bit to see if it improves conditions before going on the meds (or even to compliment them).
If you have gallstones you could make things worse by getting the bile going and moving things around and getting one lodged in a duct, so would be better to get checked first but if you search on Gallbladder Diet or Celiacs Diet and try and cut back on processed foods and sugars (eat healthy foods, fruits/vege's/rice/water, avoid transfats and saturated fats) you may help yourself before they can tell you what's wrong.
Some supplements are good to, but, hard to recommend without knowing more. DGL Licorice, Ginger, and Mastic Gum can help with unsettled stomach.