Sounds horrible! It gets better as you get older, I think - haven't passed out on the bathroom floor with cramps for some years now.
I don't know - I still get shocked how much pain I can be in some months, and it always seems to coincide with some kind of really long race.
I survived this time! I've mostly been affected when I'm running (and have definitely never passed out on the bathroom floor!), which wouldn't be a problem for a lot of people, but is nasty if running is something one enjoys.