OBJECTIVE The cause of rectal intussusception in patients primarily dominated by symptoms of anal incontinence has not been fully elucidated, especially for patients with idiopathic incontinence. METHODS Between 1991 and 1996, 51 patients referred with a diagnosis of idiopathic incontinence were prospectively evaluated by standard questionnaire, clinical examination, defecography, and anal manometry. Fourteen female patients were identified with rectal intussusception and were treated by transabdominal rectopexy. Postoperatively, clinical assessment and anal manometry were performed at regular intervals. RESULTS Continence was improved after rectopexy (P < 0.01). The postoperative increases in the anal resting pressure, maximum squeeze pressure, and maximum tolerated volume were not statistically significant. CONCLUSIONS Rectopexy improved anal incontinence in patients with rectal intussusception. The cause of rectal intussusception in anal incontinence could not be explained by functional improvement of the internal anal sphincter tone or an increase in the maximum tolerated volume. Rectal intussusception may be a cause of idiopathic incontinence in patients; however, larger prospective studies are required to support this concept.