Fecal incontinence: Transvaginal US evaluation of anatomic causes

PURPOSE: To evaluate transvaginal ultrasonography (US) as an alternative to transanal US for determining the anatomic cause of fecal incontinence in women. MATERIALS AND METHODS: Transvaginal US of the anal canal was performed in 28 women (aged 27-74 years) with fecal incontinence. A side-fire endorectal probe was inserted into the vagina and directed toward the posterior vaginal wall. RESULTS: The internal anal sphincter (IAS) and external anal sphincter muscles were imaged as independent bands in all 28 patients. The calculated mean thickness of the IAS in patients aged younger than 55 years was not significantly different from that in patients aged older than 55 years (P = .31). Posttraumatic anterior muscle disruptions were detected in 16 women; three also had rectovaginal fistulas. A rectal fistula with abscess was detected in one of 12 patients with intact muscles. All muscle disruptions, fistulas, and abscesses were surgically confirmed. CONCLUSION: Transvaginal US enables determination of the anatomic cause of fecal incontinence, allowing the surgeon to select patients who would benefit from surgical repair.