The results of the creatinine clearance test were good! Some more elaboration on that (and this is just from what I've been told; I haven't yet followed up by reading up on the test itself):
There is a routine blood test that measures the levels of creatinine in the blood. If that level goes up, it means that the body is having a hard time processing it. It is a protein, by the way. The measurement is more accurate with 24 hours of urine, apparently (jobs that suck...) and gives more information. The Boy's 24 hour urine measurement was normal, and they don't have to redo the urine test again unless the number from the blood test goes up. Which is fantastic news, not only that his kidney function is still good, but that he doesn't have to be cathed again for awhile. That was probably one of the most hellish experiences we've ever had.
And it's sad that, considering how awful it was, I don't even know if it was indeed the most hellish. Such is our life.