Prognostic significance of rectocele, intussusception, and abnormal perineal descent in biofeedback treatment for constipated patients with paradoxical puborectalis contraction. - Lau,C.W.; Heymen,S.; Alabaz,O.; Iroatulam,A.J.; Wexner,S.D. (Dis Colon Rectum, 2000)