Gallbladder attacks after medication change

After being diagnosed with severe pancolitis Aug. 1, I was taken off all previous meds and started on Lialda and 20 mg Prednisone. The Prednisone did it's job but it took about a month. I was still bleeding slightly at my follow up appt. last week so, my GI continued the same treatment for 2 more months. I started having pain in my right side sometime during this change in meds. Not bad until I rolled on my right side in the floor or in bed, then it really hurt. The night of my GI appt. I awoke to excrutiating pain in my side and back followed by extreme nausea and vomiting. Another episode occurred just a few nights later. I got in to my primary doctor and have ultrasound tests scheduled in a few days. He's pretty sure it's my gallbladder. I've also gained about 20 lbs. I know the GI is going to start me on a biologic after the Prednisone. If it's necessary to take out the gallbladder, I'm seriously thinking about just taking the colon while we're at it. Ten years of this whack-a-mole disease has me worn out. Prednisone really does a number on me. Has anyone had gallbladder problems with changes in medications or, am I just one of the lucky ones?

I have undiagnosed gall bladder issues. Mine seems to "spasm" which results in pain and very acidic stool. It doesn't happen all the time so the docs haven't been able to diagnose me.

Thanks to all for your informative replies. I have a feeling this coming year will be decision time. ActiveUCer - I may be getting back in touch with you. Thanks again.