Most people don't really give a shit where their poop goes after they get up to flush. They (me included) assume that it magically disperses never to be seen, or smelt, again. It's no different to people who do their number twos in New York. What you might interesting is that the water that flushes Mr Hanky away finds its way back into the water supply to be consumed by New Yorkers two hours later, while the doo doo ends up being sold as expensive compost to help fruit grow. Mmm mmm mmm.
Find out more fascinating faeces facts like this when you watch the short doco above detailing the journey New Yorkers excrement takes after they drop the kids off at the pool.