Something to think about...I believe that even one is too many. I believe if you are producing stones then it is time to get the gallbladder removed in a more up to date laser surgery. Too many people have had serious side effects from lithotripsies so do your online research. Doctors don't tell you that Lithotripsies are an old procedure big in the 1980's and over time research shows that a lot of people 'insides' just can not tolerate the bombarding of the stones....other organs are affected and the newer thinking is to just remove the gallbladder with the minimally invasive laser procedure. Some doctors are buying up older lithotripsy machines at a cheap price and that is all they offer so even in my town that is what is happening...so we have to travel 4 hours to a more modern clinic that offers the latest better procedures...at least they give you a choice.