There are three versions of the film available on DVD:
The Unrated Version, which replaces the original soundtrack.
The Balls-Out Uncut Edition, which retains the original soundtrack.
The Pin-Etration Edition, which has the original soundtrack, and adds hardcore inserts (fingers and penises penetrating a vagina and anus) to the gang rape sequence.
Development Hell: Gutterballs 2: Balls Deep. The back of the Pin-Etration Edition even references this, listing various crossed out dates (2009, 2010, and 2011) before just settling on "soon".