Questran (I am pretty sure that Cholestyramine is the generic name) is known to cause gas in a lot of people; many people on here have complained of it. Your nausea and bloating can be signs of gas. Ask to switch to Welchol. I and my mother-in-law are both on it with no problems whatsoever, and no one has ever complained about gas with it on here.
And you do still need to be a bit cautious with what you eat, even on the medicine. It took me a while, but I did eventually figure out that I can't have caffeine, even while taking the Welchol. Biscuits and gravy are right out, and I can only have fried food (fast food included) on very RARE occasions.
As far as I know, though, your post-gall bladder problems shouldn't have anything to do with your liver enzymes, so be sure to follow up on that problem (as I always say, nothing says that you can't have more than one thing wrong with you at a time). If you wind up NOT having Hep B, please be sure to get the vaccination for it to prevent worry about it in the future.