Qualitative assessment of anorectal junction levels and anorectal angles to investigate functional differences between constipation and fecal incontinence

Female patients consecutively referred for defecography, with either chronic constipation or incontinence, were assessed for posterior anorectal angle and anorectal junction level as measured from the ischial tuberosities. The clinical groups did not differ in grades of rectoceles, enteroceles, or intussusception. Both constipated and incontinent patients had a low resting anorectal junction position compared with that of volunteers, indicating a stretched pelvic floor. Despite this, the constipated patients achieved a similar degree of lift of the pelvic floor on squeezing as controls, and they also showed significant angle changes on lifting and straining. Incontinent patients showed a significantly smaller amount of lift than controls, a significantly larger descent than constipated patients, and no angle changes on lifting and straining. These data are consistent with significantly weaker pelvic floor muscles in incontinent compared with constipated patients, despite a similar degree of stretching