In contrast a rectal prolapse is a prolapse of tissue within/out of the retum and anus (not the vagina). In this case anal sex can be a cause owing. I just wanted to discuss this here to hear others' experiences. I am a mostly straight female in a monogamous relationship. I am into anal but. According to Pornhub, US searches for anal sex increased percent between This isn't to say that anal sex never causes rectal prolapse.