I've been on Welchol for 4 years now and would never let anyone take me off of it! If I don't have it, I have diarrhea more often than not. When I'm on it, I am almost normal in what I can eat. I certainly have a better/easier time of it than most everyone else on here with IBS. I also take the Caltrate 600 w/ Vitamin D, although it's not enough alone to control my D.
My GI doctor told me to take as many Welchol pills as I needed to stop the D. I normally take two a day, but depending on how I'm functioning, one a day might be normal. This past week I ate all sorts of naughty things, was under a lot of stress, and was coming off antibiotics, so my guts are all screwed up. So I'm taking three Welchols a day until I can get myself straightened back out. I once had to take 4 (!) when I had some biscuits and gravy and couldn't get my diarrhea to stop (needless to say, biscuits and gravy are on my "never again" list).
There have been a couple of people on here taking upwards of 6 pills a day. If you are still having some diarrhea and urgency problems, then you need more Welchol, not less. I liken it to insulin: each person needs a different amount based on that person's system, what they are eating, and the stress and other factors in their lives. If your doctor doesn't want you to have the Welchol anymore, then I suggest you do find a GI who is willing to work with you on it.
I'm the first person to not want to have to take medicine regularly, and I would rather find some way to get around having to take it, but I haven't found anything in 5 years of not having a GB that works as well and as consistently as the Welchol, so I have braced myself to being on it for life (or until they grow me a new GB in a petri dish or fetal pig). There are somethings in life that require lifetime medicine in order to have good quality of life. See my reference above to insulin!