DS1 just gave me reason to revisit this thread.
I was downstairs putting a load of washing on and he came downstairs without his nappy on and poo all over his bum and the backs of his legs. I wasn't fast enough to grab him and he turned laughing and headed back up the stairs, but he can't reach the door handle from outside so went through the catdoor. Not very pretty to watch with all the poo but the poo also got all over the catdoor and some of the screen. I have just finished cleaning it off... not fun!