Anal incontinence (AI) is defined as the involuntary loss of flatus, liquid, or stool that is a social and hygienic problem.1 It remains a complex and poorly understood condition with a multifactorial etiology. Several mechanisms, either alone or in combination, produce symptoms of AI: (a) consistency and amount of stool (eg, diarrhea), (b) damage to the mucosa of the colon and rectum (eg, colitis), (c) neurologic factors (eg, diabetes, Parkinson disease), (d) miscellaneous (eg, congenital disorders, rectocele, etc), and (e) injuries to the anal sphincter and pelvic floor muscles.
Box 35-1 Master Surgeon Box
Digital rectal examination and endoanal sonography are the most important diagnostic tests to be performed prior to considering anal sphincteroplasty.
Use 2-0 delayed absorbable suture for overlapping repairs.
Aggressive perineal hygiene via sitz baths, bidet, or handheld shower for prevention of wound breakdown is key.
Sacral neuromodulation has been shown effective in the treatment of anal incontinence.
Childbirth and anorectal surgery are the main causes because the anal sphincters and the pudendal nerve may be damaged.2,3 Minor degrees of fecal soiling due to internal anal sphincter (IAS) injuries have been reported after hemorrhoidectomy, mucoprolapsectomy, manual anal dilatation, or lateral internal sphincterotomy.2,3 Obstetric trauma to the anal sphincter is invariably restricted to the area anterior to a horizontal line through the mid-canal. Injury of the anal sphincters posterior to this line is usually due to some other etiology such as trauma or fistula-in-ano. Obstetric anal sphincter trauma may involve part or the full length of the sphincter and can be partial or full thickness.3-5 The majority of obstetric injuries are associated with a single, large defect in the external anal sphincter (EAS) between 9 and 3 o’clock but can also involve the internal sphincter. Fistula surgery can also be responsible for damage to the anal sphincters and up to 60% of patients can become incontinent following treatment of complex, high fistulas or after multiple operations for a recurrent or persistent fistula.6
A systematic evaluation is fundamental to reveal the underlying pathophysiology and lead to appropriate therapy. The first step in evaluating patients suffering from AI is always a careful history. Questions should focus on type and degree of incontinence as well as on changes in the patient’s lifestyle. A scoring system such as Williams, Pescatori, Wexner, and AMS is often used to rate incontinence more accurately. Assessment of patient’s quality of life (QoL), using specific questionnaires such as the Fecal Incontinence Quality of Life Scale should be considered useful parameters of this disorder.7
In daily clinical practice, endoanal ultrasonography (EAUS) is an important diagnostic tool to identify sphincter lesions and defects8 and it has been defined as the gold standard investigation in the assessment of anal sphincter integrity by the joint report of the International Urogynecological Association (IUGA)/International Continence Society (ICS) on the terminology for ...