Mine bp just did that as well...he hasn't pooped in ~6 weeks. I feed hime one small adult rat a week.

He finally pooped yesterday and I have to say that it was massive. I actually took a picture of it cause I've never seen anything like this before since I've purchased him.

and it was real real stinky, I cleaned out the cage and it still stinks...I'm gonna have to break out the bleach