I never worried much about stones I often did not have any, as long as I saw bile then I knew the flush worked. Officially (ultrasound) I have one big stone I still have it but you can live with it just keep your liver clean, I mainly flushed so I would not make new ones.
I had never pain afterwards but some people do. You can read Telman's posts he has written about it. He has also a blog he made of his journey, but I can't remember the link.