Forty-two patients complaining of constipation with abnormal anorectal motility were studied: 20 children and 6 adult females had a decreased rectoanal inhibitory reflex (RAIR) amplitude and 16 adult females had anal hypertonia and ultra slow waves (USW). Biofeedback training was used to condition the patients to relax the anal sphincter during the desire to defecate. After two to eight (mean, 4) training sessions, the authors observed simultaneously a normal RAIR amplitude and recovery from constipation for at least six months in 15 children and five females with decreased RAIR amplitude. Nine of the adult females with hypertonia and USW were able to suppress USW but did not recover from constipation. The data suggest that biofeedback training could be useful in some groups of constipated patients.