Differences in anorectal manometry between patients with haemorrhoids and patients with descending perineum syndrome: implications for management.

Anorectal manometry was carried out at rest, during balloon distension of the rectum and during rectal infusion of saline in 19 patients with haemorrhoids, 30 patients with descending perineum syndrome and 21 controls. Basal and squeeze pressures were significantly higher in patients with haemorrhoids than patients with the descending perineum syndrome. A lower rectal volume was required to inhibit internal sphincter tone in patients with descending perineum syndrome compared with control subjects or patients with haemorrhoids. During rectal infusion of saline basal and peak anal pressures in patients with the descending perineum syndrome were lower than in haemorrhoid patients. Peak rectal pressure was abnormally high in both groups. These differences in anorectal function suggest that despite a similar presentation, the two conditions have a different pathogenesis. Moreover, inappropriate anal sphincter stretch or mucosal excision in patients with descending perineum syndrome may lead to severe incontinence.