I can't say that I have an explanation, but I am having a similar problem. I usually only have the urge to go twice a day so it has not been a real serious concern of mine yet. I just figured it was a side effect of one or of or a combination of my medications. I meant to ask my doctor about it the other day, but it just slipped my mind.

If it continues for too much longer, I would seek medical treatment as soon as possible. Even if it means going to the ER.