My g/f (now wife) used to get them a lot.. She is a nurse and she said it was from too much sex.. I told her you cannot have too much sex... They have reduced now that we are not like rabbits in heat in the early days of our relationship...

I have heard that cranberry juice helps a lot.. Not just when you have symptons but as a bit of a preventative measure as well... Water is always good for you too but the cranberry juice is said to help...