The Original Dark Ending
Over the past 30 or so years, the story behind the original dark Pretty Woman script has been flattened out into a trivial footnote. The most popular version of the story (the one we find on Wikipedia and IMDb) is actually a much longer saga. Executive producer Laura Ziskin was the person who demanded that the Garry Marshall–directed version of the movie have a feel-good ending.
Source: jwa.org
This turned the film from a dark drama into yet another Disney fairy tale, even though it did have a modern twist that involved prostitution. “I didn’t want a movie whose message would be that some nice guy will come along and give you nice clothes and lots of money and make you happy,” Ziskin said in a 1991 interview with People magazine.