Total gastrointestinal transit time (TGITT), frequency of defecation, and anorectal manometry were evaluated in 63 pediatric patients referred for chronic nonorganic constipation; in 39, segmental transit times of the right and left colon and rectum were also measured. TGITT was significantly longer in chronically constipated children than in matched normal controls. Although bowel frequency was highly significantly correlated with TGITT in patients with prolonged transit time, not all children with prolonged TGITT had reduced bowel frequency. Moreover, not all children with constipation had prolonged TGITT. In children with idiopathic chronic constipation, slowing of intestinal transit occurred most frequently at the level of the distal colon and rectum. Anorectal motility variables were not significantly different in children with functional chronic constipation and in normal children. Maximal resting and pressure and mean intrarectal distending volume causing threshold inhibition in constipated patients did not significantly differ from the control values. Therefore, anorectal manometry did not detect relevant motor abnormalities in constipated children.