I was in terrible upper right quadrant pain prior to my first flush. All I know is that my pain started to rapidly diminish after my very first flush, and now that I'm on #6, I can say without a doubt that my pain is gone. I will continue to do them every 2-3 weeks until I do not get any more stones.
I could care less what those things coming out of my body are. But it's great sport anyway.
I don't listen to any nay-sayers. I know what I know, and that's all that I know.