Two small mice depending on the size of the animal might not be enough. How big is your BP?

Also keep in mind that young animals utilize most of the prey item for growth so if the food intake barely meets their needs due to their high metabolism it leaves little to nothing to eliminated.

DO NOT SOAK your BP unless there is a reason too, that means blockage which would be visible (persistent bulge near the cloaca that is not going away) even than bath are not necessary as you can help by slightly massaging the waste out of our snake - Again only if necessary.