The purpose of this study was to determine whether biofeedback benefits children with dyssynergic defecation and constipation/encopresis, and whether home biofeedback improves long-term outcomes. Thirty-six patients with chronic constipation who had failed at least 6 months of conventional treatment and demonstrated dyssynergic defecation at anorectal manometry were randomized to biofeedback in the laboratory alone (group 1, n=24) or in the laboratory and at home (group 2, n=12) and followed up at 2, 4, and a mean of 44 months. Thirty patients were available for long-term follow-up. Bowel movements increased in all from a mean of 1.4/week to 5.1, 5.8, and 5.1 per week at 2 months, 4 months, and long-term, respectively (p < or = 0.001). Soiling decreased in all from a mean of 5.5/week to 0.6, 0.1, and 1 per week at 2 months, 4 months, and long-term, respectively (p < or = 0.001). Laxative use decreased from a mean of 4.1 days/week to 0.6, 0.3, and 0.7 per week at 2 months, 4 months, and long-term, respectively (p < or = 0.001). Twenty-seven of 30 parents ranked their satisfaction a mean of 2.2 (range 1-excellent to 3-good). There were no significant differences in outcomes between the laboratory alone group and the laboratory plus home group. Biofeedback is beneficial for some children with chronic constipation and dyssynergic defecation. Supplemental home biofeedback does not improve long-term outcomes.