Parameters of anorectal and colonic motility in health and in severe constipation

Abstract
Anorectal function and colonic transit was assessed in 17 severely constipated patients and 15 age-matched controls. The constipated patients were divided into those who had “immobile perineum” (perineal descent ≤1.0 cm during attempted defecation) and those who had a normal descent (>1.0 cm) of the perineum. When constipation was accompanied by an immobile perineum, patients had impaired balloon expulsion, impaired and delayed artificial stool expulsion, decreased straightening of the anorectal angle, decreased descent of the pelvic floor with defecation, and prolonged rectosigmoid colon transit compared with the patients with constipation who had a mobile perineum and with normal controls. The mobile-perineum group differed from controls only in colon transit times, having prolonged total colon transit. Anal sphincter resting pressures, immediate artificial stool expulsion, resting anorectal angles, and electromyography of the external anal sphincter and puborectalis did not differentiate the constipated patients from the controls. We concluded that descent of the perineum of