Vanishing Pee

Q: So last night I took a Benadryl and went to bed. I figured I wouldn't sleep too long because at the time I already had to pee really bad. When I woke up some 4 hours later I no longer had to pee at all. And I didn't wake up in a puddle of my own filth. So Doug, where did the pee go?

A: You were visited by the Pee Fairy.