Anal sphinctermyectomy according to Lynn is an established therapy for chronic constipation in children. However, no consensus on indications exists and, according to the literature, results are contradictory. In order to clarify this problem, 33 children were examined and divided into two groups: I (n = 12) chronic constipation, and II (n = 21) dysganglionosis. All children were treated conservatively for at least a 6-month period and showed elevated anal resting tone in manometry. The operative results were assessed by anorectal manometry and a physical examination; subjective opinion was evaluated using a questionnaire. Anorectal manometry showed a marked decrease of anal resting tone of 30%, correlating to subjective relief of the symptoms.