How do I make wise decisions for medical care?

One of my mother's doctors has gone on to a teaching position or something like that. Anyway, the doctor that left his place bounced into the room at Mom's next visit, never introduced himself, looked at the paperwork and said, "You need an operation, you need an operation..ha ha ha ...???????? What doctor does that? Now he has tried two times to send my mother to other doctors despite the fact that Mom doesn't want an operation (no symptoms) and to me is treating her like a specimen to be shared with other doctors because she has good insurance. My Mom is 95 and she and I are tired of going to more and more doctors. It is stressful and she is in reasonable good health. They found a large gall stone (which cannot pass and isn't causing pain), they say she needs a bone scan. Well, I want to talk to her regular doctor first. Does anyone else have this kind of problem? I don't want to not take her if she needs a doctor, but I am not going to take her the rounds to make someone money and fill up their appointment calendar.
Thanks for your input.