Anal Incontinence and Anal Sphincter Rupture during Childbirth – Prevalence, Diagnosis and Treatment

...................................................................................................................9 INTRODUCTION ......................................................................................................11 REVIEW OF THE LITERATURE .............................................................................13 1. History of anal incontinence ..................................................................................13 2. Epidemiology of anal incontinence .........................................................................13 2.1. General ...........................................................................................................13 2.2. Obstetric anal incontinence .............................................................................13 2.2.1. Incontinence after third or fourth-degree anal sphincter rupture ..............14 2.2.2. After an occult anal sphincter defect ........................................................14 2.2.3. After caesarean section .............................................................................15 3. Pathophysiology of anal incontinence .....................................................................15 4. Structure of the normal anal canal ..........................................................................15 5. Etiology of anal incontinence .................................................................................16 5.1. Obstetric causes of anal incontinence ..............................................................16 5.1.1. Anal sphincter rupture .............................................................................16 5.1.2. Nerve injury ............................................................................................17 5.2. Non-obstetric causes of anal incontinence .......................................................18 5.2.1. Incontinence with normal anal sphincters ................................................18 5.2.2. Incontinence with abnormal sphincters ....................................................19 5.2.3. Other reasons ..........................................................................................19 6. Risk factors for anal sphincter rupture during childbirth ..........................................19 6.1. Instrumental delivery ......................................................................................19 6.2. Primiparous status ...........................................................................................20 6.3. Episiotomy .....................................................................................................20 6.4. Other risk factors ............................................................................................20 7. Classifi cation of symptoms of anal incontinence ......................................................20 8. Diagnostic evaluation of anal incontinence ..............................................................21 8.1. Anamnesis ......................................................................................................21 8.2. Clinical examination .......................................................................................21 8.3. Endoanal ultrasound examination ...................................................................22 8.4. Anal manometry .............................................................................................22 8.5. Electromyography ..........................................................................................23 8.6. Pudendal nerve terminal motor latency measurements .....................................23 8.7. Magnetic resonance imaging ...........................................................................23