The Little Madam currently finds poos and wees incredibly funny. It's not the poos and wees in themselves that make her laugh, more the words. Like, she'll use either word to describe just about anything and everything, and then giggle uncontrollably.
I found it amusing the first dozen times, but now I just roll my eyes and wish I hadn't inadvertantly encouraged TLM to use "poo" as a universal adjective. We adults may think it pretty tiresome, but she sure hasn't gotten tired of it yet.
I'm quite certain that this is just one of those things that all young children go through. But I never realised it would start so damned young.