Oh that's happened to me.
Question is, do you run faster to get to the loo quicker but then...erm... well shake things around a bit more than you would like, or do you go slower and walk :confused: I have had to pop in tescos loos a couple of times in an emergency :o
Oh anyway, I did a couple of miles at lunchtime and was crap, I don't think I will ever be able to run again :(