A rectal buttonhole tear is a rare obstetric complication, comprising an isolated tear of the rectal mucosa and vagina without the involvement of the anal sphincter complex. 1 The incidence of buttonhole injuries after delivery is low, with descriptions limited to case reports and case series. 2 These tears typically occur with minor degrees of perineal trauma and so have the potential to remain undiagnosed unless a careful combined vaginal and rectal examination is performed. While, by definition, they are not fourth-degree tears as both sphincters are intact, if a rectal buttonhole tear goes undiagnosed it can evolve into a rectovaginal fistula-a similarly uncommon obstetric complication with severe short-and long-term morbidity. 3 Repair techniques for these injuries vary considerably, and, owing to the rarity of such injuries, there is no clear consensus on acute management of these tears. A potential standardized repair technique has been suggested, 2 though is supported by sparse evidence. Given the similarities with rectovaginal fistulae, 4 most buttonhole repairs are performed along similar principles, with primary

No abstract