In the original script, Rabbit left the house to discover that an entire subdivision had been built up unbeknown to him, filled with children and families, all unaware of the horrors going on inside the house.
The original script called for Bob to keep pieces of his victims in jars and cut off Rabbit's thumbs. When Jennifer Lynch took on the project, she did some re-writes to reduce the violent nature of the film.
Some viewers complained that the ending of the film felt rushed and tagged on. Jennifer Lynch said that the ending made more sense in the script, but due to time and budget constraints, it wasn't able to be executed properly.
The original focus of the story involved detectives actively pursuing Bob, who they nicknamed "The Dicer" for his habit of cutting women up before killing them. The relationship between Bob and Rabbit was secondary.
Was originally rated NC-17 by the MPAA for "some explicit violence" but the film was later edited to achieve an R rating for "disturbing and sadistic violent content including bloody killings and rape, and for language and sexuality."