Fecal incontinence: a review of prevalence and obstetric risk factors.

Anal incontinence (AI) is a significant problem that causes social and hygienic inconvenience. The true prevalence of AI is difficult to estimate due to inconsistencies in research methods, but larger studies suggest a rate of 2-6% for incontinence to stool. There is a significant association between sonographically detected anal sphincter defects and symptoms of AI. The intrapartum factors most consistently associated with a higher risk of AI include: forceps delivery, third or fourth degree tears, and length of the second stage of labor. Fetal weight of > 4,000 g is also associated with AI. Repair of the sphincter can be performed in either an overlapping or an end-to-end fashion, with similar results for both methods. The role of cesarean delivery for the prevention of AI remains unclear, and further study should be devoted to this question.