Hello Cristina, I am writing this email to thank Dr. Clark and all of you. Finally I managed to do the urotac with contrast medium prescribed to me by the urologist and the result ... the uric acid and oxalate stones are gone !!! So the only cure for my recurrence is to cleanse my kidneys once a year !!! If I had known before I would have avoided having operated 3 times kidney stones !!! Thanks to a client of mine, however, I discovered Dr. Clark's treatments !! Now I have also recommended it to a client of mine who also has a kidney stone problem !!!