# Much of the gore has been edited out to get an R-rating in the United States and also for the UK release. The Spanish release is uncut.
# The first cut of the film, which was released in Spain, contains hardly any gore and was more of a straight-up thriller. Most of the gore scenes were re-shot and added for the US and UK releases. Scenes that only appear in the original (Spain) version:
* After Jennifer escapes it shows a shotgun on the floor along with a blasted door
* Also after she escapes there's a scene that shows people wondering how she got out
* There's more investigating and police work with the two male cops and there's a also a female cop who doesn't appear in the other version
* Ben has an extra scene at a restaurant and more overall screen time Scenes that were added to the second (US/UK) version:
* The acid shower scene
* The flashback scenes with Gary and Ben as kids
* The blender scene
* The tooth-pulling scene
* Jennifer being abducted at the nightclub
* All of the dog scenes
* The scene where Jennifer is on her cell phone
* Jennifer and Gary fighting over the gun
* Jennifer shoots Gary an extra time (in his crotch)
* The videotape of the woman in the acid trap
* The scenes that show some of the aftermaths of the other victims