[Delivery and anal incontinence: definition, classification, prevalence and pathophysiology]

Summary of the mutual relationship between vaginal delivery and anal incontinence.

Review.

Department of Gynecology and Obstetric, Charles University and Faculty Hospital Pilsen.

Review of the current international literature covering the given problem. Anal incontinence is defined as an unvoluntary leakage of flatus, liquid or solid stool. Fecal incontinence means the leakage of liquid and solid stool only. Women are at eighttimes higher risk of developing anal incontinence (the leakage of flatus, fluid or hard stool). The main reason considered to be the cause of this difference is a birth. Postnatal anal incontinence is a disabling problem for as much as 13-20% of women. Review describes classification, prevalence, incidence and cause of AI in women considering maternal position at birth, second stage of labor, breastfeeding, anal sexual intercourse and multiple births. Two main pathogenetic mechanisms are presented. 1) Perineal neurological injury is described in earlier studies. This looks to be the major reason for 3rd and following vaginal births. 2) An apparent or occult anal sphincter tear seems to be the main factor particularly for the 1st vaginal birth. 2.3% of primigravidae have an apparent tear and 35% sonographically detected occult anal sphincter tear. Anal incontinence develops nearly exclusively in these groups. 42% of afflicted women complain of impaired quality of life. Anal incontinence appears to be improved within the time (in 36-76%). Longterm outcome is not known yet. The postnatal check-up should also include the question of de novo developed anal and urine incontinence or impaired sexual health.