Some constipated women have difficulty relaxing the striated muscles of the anal sphincters, sometimes called anismus. This study was developed to provide a biofeedback-based relaxation treatment to teach these patients to relax the "voluntary" anal sphincter muscle in order to assess whether this treatment would be effective in reducing symptomatology. Seven constipated patients who were unresponsive to a high-fiber diet and required persistent laxative dosing to achieve regular bowel frequency were studied. A dual-therapy approach, in which patients were taught to relax the anal sphincter muscles via biofeedback from a manometric anal sphincter probe, was used. Concurrently, patients were instructed in general biofeedback-relaxation techniques. All were treated as outpatients. Complete data were collected on five patients, one patient discontinued therapy, and one patient moved after treatment was completed. Stool frequency improved from a mean of 1.9 per week to a mean of 4.9 per week in six patients (P less than 0.05). In the five patients who completed the entire protocol, pain and bloating symptom levels were compared before and after treatment. Abdominal pain grade was reduced from 12.8 per week to a mean of 4.4 per week (P less than 0.05), and bloating was reduced from a mean of 14.3 per week to a mean of 6.0 per week (P less than 0.06). Follow-up of 2 to 4.5 years posttherapy showed continued improvement in bowel function and abdominal symptomatology. This treatment appears to be effective in improving stool frequency and in reducing the associated abdominal pain and bloating symptoms in constipated women with anismus.