Objective: To assess the use of endoanal ultrasounds to identify anal pain etiology in patients with either spontaneous or post-operative pain, and to review the most frequent causes.
Methods: A descriptive study of ultrasound findings in patients with anal pain during the last six years was performed. All ultrasound scans were performed using a B&K Diagnostic Ultrasound System (Cheetah 2003, B&K Medical, Gentofte, Denmark) with a 7-MHz endoprobe providing 360 degrees images.
Results: Ninety-five cases of anal pain were studied by endoanal ultrasonography. Sixty-seven cases of anal pain ocurred in patients with previous perineal or pelvic surgery: anal fissure (48), Hemorrhoidectomy (12), episiotomy (4), fistula (2), and prostatectomy (1). After fissure surgery, incomplete sphincterotomy was the first cause of anal pain. Twenty-eight patients had no previous surgery, and more than 57.14% of them were found to have internal anal sphincter hypertrophy.
Conclusions: Patients with anal pain can be studied by endoanal ultrasounds in spite of the use of an endoprobe. With this exploration a cause of pain is found in 81.93% of cases. Internal anal sphincter hypertrophy is the most frequent finding associated with spontaneous anal pain.