The forum automatically censors out that word, so I wasn't sure what it was until you said urinate.

I have some small experience with this, so:

Are you taking any caffeine before you go to bed?
Do you drink at all before bed?
In general, do you have any activity you do before bed on a consistent basis?
Are you able to go to the bathroom if you entertain this feeling?

-Ramon http://razor.ramon.com