Thanks for your response, Chris. We always did blood draws when my son was small too and they were always extremely stressful. He never got used to them no matter what I promised him! :)  It frightened him so much that there was absolutely no reasoning with him. I am trying to remember when exactly it was that we started the 24 hr. collections. I think he was 4. It was a welcome relief but also because our doctors truly feel that they keep better control with the urine rather than the blood alone. So far they have been right because our son has been extremely well controlled from day 1. I am looking forward to hearing back from you when you start so please remember to let me know. Feel free to e-mail  me privately if you like. Thanks for your response.                           Valerie