[The importance of diagnostics in faecal incontinence. Endosonography].

Endoanal sonography is a well established method for the morphological diagnosis of anal sphincter damage. The best images are obtained using a 7-10 MHz rotating rigid endoprobe. The internal anal sphincter and the external anal sphincter, as well as the other pelvic floor structures, can be clearly visualised with this technique. Endosonography has shown physiological differences in sphincter anatomy and brought new insights into the pathogenesis of anorectal disorders. Apart of anal fistulas, faecal incontinence represents the main indication for the use of this method. In addition, rectal evacuation disorders are an indication for which endosonography allows a first step towards a diagnosis. Anal ultrasound is a technique friendly to both the physician and the patient, and belongs in every coloproctological unit for the assessment of faecal incontinence. Accuracy, specificity and sensitivity for the detection of anal sphincter defects range between 83 and 100% in almost all studies. Additional methods are vaginal endosonography, three dimensional endosonography and perineal sonography.