This review is both of the book and the film.
Although they have the same title, the plots are quite different in places. And some of the sub plot is missed out such as the one about Bridget’s builder.
This is a sequel to Bridget Jones Diary, which was based on Pride and Prejudice. However, part of the plot of The Edge of Reason is based on another of Jane Austen’s novels – Persuasion. Mark and Bridget break up because of Bridget putting her friends’ needs before Mark’s and because of her reliance on self-help books. Mark becomes interested in Rebecca but while away on a weekend break, she insists on jumping off a bridge against all common sense and injures herself. This is paralleled in Persuasion in the scene in Lyme.
I prefer the book as I think the film alters the plot to play to the popularity of scenes in the first film – Bridget Jones Diary . For example, the stupid and pointless fight between Mark Darcy and Daniel Cleaver. clearly put in because of the fight in the first film. Plus Rebecca’s motivation is completely altered. In the book, she is scheming after Mark but in the film, it is revealed that she is romantically interested in Bridget. Also, Bridget comes across as an idiot in the film.