Fast for IBS

Hey Everyone.
I've been suffering from IBS for nearly a decade.
I've determined that this summer I'm going to embark on an extended fast in hopes of eliminating my issues.
Has anyone else been successful in reversing IBS symptoms with a long fast?
I'm thinking 21 days but will go as long as I need to ensure positive results. Any recommendations?

Also - any general suggestions for making this successful are greatly appreciated.