I suffered ALOT with gallbladder attacks all through my second pregnancy. Here are some notes from my experience:
1.) Diet may or may not help. I am a pretty low-fat eater, it didn't seem to matter what I ate...they came when they came. I remember one night groaning in pain and being like, "I ate grilled chicken breast and broccoli!!! WTH!!!??"
2.) For awhile, when they weren't at their worst, a granny smith apple once a day would help stave them off. I know, weird. In fact, sometimes, when I felt one coming, if I ate the apple right then, it would calm down. (Later that stopped working, but it did the trick for awhile)
3.) Gallbladder 'cleanse'.... please check with your doctor before you do this, but it did help me for awhile... look it up online to get the exact directions, but you basically ingest nothing but apple juice or apples for a day, then (this is really gross) drink a cup (yes.... a cup) of olive oil with some lemon juice mixed in (you can blend it with grape juice to help get it down. Either way, it's sick.) Keep it down for a few hours, then drink an epsom salts solution....and STAY AT THE TOILET. You'll be...ermmmm... occupado for awhile.
The idea is that the olive oil both lubricates the gallbladder and sends your gallbladder into overdrive because of the fat content, and hopefully expels alot of the little stones. Then the epsom salts solution helps you pass the stones completely. This did not cure it altogether, but kept attacks away for a few months for me after only doing it once. Ultimately, I ended up getting the surgery when my son was a few months old. I got so bad I got to the point where I was having DAILY attacks.
**I only say check with your doc because I'd hate to recommend something that has some hidden danger to pregnancy that I'm not aware of.... I'd think it's fine, it's all food, really, but you never know. I had already delivered my son by the time I got desperate enough to try this.
4.) If all else fails, when an attack hits, put a heating pad on your upper back while also holding an ice pack to your sternum. It helps. And.. if anyone in your house has leftover vicodin from some injury or pain incident, take one. It is safe in moderation during pregnancy and REALLY takes the gallbladder pain away.
Whew. That is from a sufferer of MEAN gallbladder pain, and my desperate attempts to deal with it without surgery. In the end, I had the surgery, and am very very glad I did.