I was scheduled for gall bladder surgery several years ago but cancelled the surgery after hearing from friends/co-workers how removing it can cause problems controlling your bowels. My mother has had that problem ever since her surgery years ago.
There were two times when I was hurting pretty bad and ended up driving myself to the emergency room the second time. They immediately checked to make sure I wasn't having a heart attack. After ruling that out they left me in the ER for an hour or so. By the time they finally took me to a room the stone had moved or whatever it does and I was fine. They tried to give me pain meds but by then I didn't need it and ended up driving myself back home. In that case it could have been brought on by eating too much ice cream. That is one thing I read that will trigger the 'attacks'.
I found instructions on the internet how to flush gall stones out and it worked for me. Since doing the flush, I have had no more problems. If the gall bladder is seriously diseased that may not work.
Your friend may want to do more research and get a second or third opinion on whether the surgery is really necessary.