Significance of pelvic floor muscles in anal incontinence.

Abstract

The pathophysiology of anal incontinence may be elusive using current parameters. Our aim was to establish the role of the levator ani in anal continence. In 53 patients with anal incontinence, 30 with constipation as disease controls, and 15 healthy controls, we evaluated incontinence severity by a 0-12 scale, anorectal function by standard manometric tests, and levator ani contraction by a perineal dynamometer. Patients with incontinence exhibited various physiologic abnormalities (3.2 +/- 0.3 per patient), but multiple regression analysis showed that levator ani contraction was the independent variable with strongest relation to the severity of incontinence (R = -0.84; P < 0.0001), as well as a predictive factor of the response to treatment (R = 0.53; P < 0.01). Furthermore, in contrast to other physiologic parameters, clinical improvement in response to treatment (4.4 +/- 0.5 score vs. 7.9 +/- 0.5 score pre; P < 0.001) was associated with a marked and significant strengthening of levator ani contraction (448 +/- 47 g vs. 351 +/- 35 g pre; P < 0.05). We have shown the importance of levator ani failure in understanding the etiology of anal incontinence and in predicting response to treatment.