Physiology and pathophysiology of the anal sphincters.

Anorectal anatomy, physiology and pathological changes may be readily assessed by clinical examination. More objective investigation is provided by anal manometry and by electromyography (EMG) of the striated sphincters. At present single fibre EMG is the most reliable method to detect pelvic floor neuropathy, which is a common cause of the so-called idiopathic fecal incontinence.