ABSTRACT
Neurogenic injury of the external anal sphincter and pelvic floor musculature is important in the pathogenesis of fecal incontinence. The anorectal angle is maintained by the anterior pull of the puborectalis, which plays a role in maintaining continence. The angle is acute in normal subjects and frequently obtuse in patients with idiopathic fecal incontinence. Loss of anorectal angulation was therefore thought to predispose to fecal incontinence. Physiological assessment of these patients has, in general, been unhelpful in correlating clinical outcome with anatomical and physiological variables. A. G. Parks described the procedure of postanal repair as a means of restoring the anorectal angle and increasing sphincter length primarily in patients with idiopathic fecal incontinence. The chapter argues that the mechanism of restoration of continence following postanal repair is improvement in sphincter function rather than improvement in anorectal angulation. It shows an improvement in both resting and maximum squeeze pressures in those patients whose continence status improved postoperatively.
