[Endo-anal sonography in diagnosis of fecal incontinence]

Endoanal ultrasound is a new imaging technique in the diagnostic work-up of patients suffering from anal incontinence. A standardised examination as well as hardware specific reference values for the sphincter muscles are of paramount importance to allow correct interpretation of the continence organ. At the University Hospital of Würzburg from 1.2.1993 to 31.7.1994 90 patients (50 male, 40 female; age: 16-81 y.) with normal continence underwent endosonographic assessment of their sphincter complex. We measured the internal anal sphincter (IAS), puborectalis muscle as well as the three separate parts of the external anal muscle (EAS). Apart from establishing reference values we found a significant increase in thickness of both EAS and IAS with increasing age. However, no correlation was seen between muscle thickness, sex, height or weight. We also examined 29 patients with a history of incontinence. 13 (45%) had a morphological sphincter defect, most of which were due to obstetric trauma or previous proctological operations. 10 (35%) patients suffered from so called idiopathic incontinence. Anal ultrasound in these patients revealed muscle hypotrophy of the structurally intact sphincters.