Hi Shiva'smom!
I'm so sorry that you are experiencing this! I get stomach pains like that from time to time, and I know how miserable they can make a person.
I looked up Mycobutin and one of the (Ha!) "less serious" side effects are stomach pains, so I would suggest that you call your doctor and ask for a change in medication. Here is where I found the info:
www.rxlist.com/mycobutin-drug/patient-images-side-effects.htm I do hope that you feel better soon!!!