River of Fundament is a 2014 operatic experimental film written and directed by American artist and filmmaker Matthew Barney, and co-directed by longtime collaborator Jonathan Bepler. It was produced by Barney and the Laurenz Foundation and is loosely based on the 1983 novel Ancient Evenings by Norman Mailer. The film features Barney, Dave Bald Eagle, Milford Graves, John Buffalo Mailer, Ellen Burstyn, Maggie Gyllenhaal, Madyn Greer Coakley, Paul Giamatti, Shara Nova, Joan La Barbara, Elaine Stritch, Debbie Harry, and Aimee Mullins.