Long-term anorectal function was assessed in children operated on using Duhamel's technique for Hirschsprung's disease. The files of 75 patients (16 girls and 59 boys) operated on between 1977 and 1991 were reviewed. Questionnaires were analysed on 63 (12 girls and 51 boys) over 2 years of age. The median age at completing the questionnaire was 6.6 years. Forty-one of these 63 patients had aganglionosis of the rectosigmoid, 15 of a long colonic segment, and 7 of the total colon. Of 14 children age 4 or less, 6 had severe constipation, whereas 8 had regular spontaneous defaecation. Ten of the 49 over 4 years of age were continent without constipation, 22 had soiling and/or constipation, and 17 were incontinent, one of whom had a permanent colostomy. There was no correlation between age or sex and anorectal function. Anorectal function in children with long segment was not worse than in those with rectosigmoid aganglionosis, but only 1 of 7 with total colonic aganglionosis was continent. Because many adapt themselves to the handicap, symptoms are often underreported. A detailed questionnaire appears to be a reliable tool for elucidating the real situation. A systematic follow-up of patients with Hirschsprung's disease is proposed to anticipate the complications and to institute proper measures at an early stage.