Kris, start by following a low fat diet. Many people have a problem processing fats the way they did before surgery, so it may be of help.
If the diarrhea is severe, talk to your doc about the use of questran, which is a bile-binding resin. It may be of help, but you're going to have to figure out just how much to use since using too much can cause constipation.
If you're having pain like what could be called a 'gallbladder attack' then you need to talk to your doc about the possibility of sphincter of Oddi dysfunction (SOD). Many docs will deny it exists and some don't know about it, so do some reading.
In the meantime, also ask your doc about the use of an anti-spasm med like bentyl. It has to be used in fairly high doses, but it might help.
I has my gallbladder removed as well. I read something before the surgery about possible problems and something that stuck with me sounds a lot like your story. There is a duct that secretes the bile the the gallbladder holds. Sometimes, even after the gallbladder is removed (and the way I understand it, most doctors remove the duct as well) there can be problems with the duct if it is not removed. It was difficult enough for me to find a doctor who would actually listen to me and run the correct tests on my gallbladder; I imagine some doctors would brush you off if you made this suggestion. But, it is something I would definately keep in mind.