Clinical and manometric evaluation of anal sphincter function in patients with rectal prolapse.

We studied 27 patients with rectal prolapse (7 men and 20 women). Eight patients were continent, 8 were partially incontinent, and 11 were totally incontinent. Perineal descent and an absent anocutaneous reflex were common findings, implying damage to the external anal sphincter and the pelvic floor muscles. Both partially and totally incontinent patients had significantly lower basal and voluntary contraction pressures compared with those of control subjects, which is in accordance with previous reports on the subject. Our continent patients had normal voluntary contraction pressures, but basal pressures were lower than those of the control subjects (p less than 0.02). This suggests that there may be dysfunction of the internal anal sphincter before the development of clinical symptoms of incontinence. The internal anal sphincter reflex was present in 19 patients (70 percent). It was absent in patients with very little tone of the anal canal. It seems that absence of the internal anal sphincter reflex is not invariably connected with rectal prolapse. The results of this study indicate that rectal prolapse is often associated with dysfunction of the anal sphincters, leading to incontinence.