Ultrasound study of anal fistulas with hydrogen peroxide enhancement.

Purpose: This study was designed to evaluate the effectiveness of hydrogen peroxide-enhanced, endoanal ultrasound in the assessment of fistula-in-ano and compare ultrasonographic results with the surgical outcome.

Methods: A total of 80 patients with anal fistula were studied prospectively by physical examination and endoanal ultrasound enhanced with hydrogen peroxide. We used standardized ultrasonography and operation notes.