Anorectal Incontinence: Aetiology, Pathophysiology and Evaluation

Faecal incontinence is a complex problem, often of multifactorial origin. Although the condition is widely accepted as a problem in the elderly, it is now becoming apparent that much younger age groups are frequently affected. Its exact incidence is about 2% of the general population, while in other individuals, the prevalence has been reported to approach 60%. Despite the considerable advances that have been made the past decades in the evaluation of anorectal incontinence, our understanding of it remains limited. A thorough history, good physical examination, and detailed anorectal physiological investigations can help the therapeutic decision-making algorithm. Complete functional and anatomical assessments of the anorectum, anal sphincters, and pelvic floor are mandatory in all patients with faecal incontinence to correctly identify the cause and type of incontinence and allow correct treatment. Anorectal manometry is used to establish the presence and extent of the weakness degree of the pelvic floor sphincter muscles, allowing an objective measure of resting and squeeze pressure. Anal endosonography is a very valuable tool in planning restorative surgery or in assessing results after sphincter repair. Because electromyography may detect functional abnormalities, the two techniques are complementary and not mutually exclusive. Determining the most appropriate tests will largely depend on the patient's history and symptoms and can vary for each patient.