Postanal pelvic floor repair

Postanal repair was developed by Sir Allan Parks in the 1970s [1] and popularised in the early 1980s for patients with neuromyopathic faecal incontinence. The original objective of this operation was to restore the anorectal angle, which was thought to be an important factor in continence. In 1975, Parks suggested the flap-valve theory that stressed the importance of the acute anorectal angle. According to this theory, a rise in intra-abdominal pressure caused the upper end of the anal canal to be occluded by anterior rectal mucosa, preventing rectal contents from entering the anal canal. Neuromyopathic faecal incontinence was associated with perineal descent and an obtuse anorectal angle, which rendered the flap-valve-like mechanism ineffective. Further investigations, however, failed to show changes of the anorectal angle, and currently, it is thought that an improvement of muscular contractility is responsible for any improvement in continence [2].