I used the services of Kraft, Panvini, Nuddell when I had kidney issues over the last 5 years, they are a nice clean practice but I never ever saw kids in there,(I also felt like the only woman being treated there too!), everyone else in the waiting area always seemed to be your "typical" older male patient. I'm assuming if you were referred to them they do have someone with pediatric experience however aas I mentioned I never saw kids there and it does not eem like the office is geared at all towards kids (no toy/ magazines/etc) . Have you tried going on the Lucille Packard Childrens Hospital website and getting "true" pediatric urologists contact information from there?... I have always managed to get good specialist referals in this way.
Good luck hope i all works out for your son.