Segmental colonic motility in patients with anorectal malformations

Constipation is one of the most important functional sequelae in patients with anorectal malformations. The cause of this motility disorder is unknown.

The purpose of this study was to assess total colonic transit time (TCT) and segmental colonic transit time (SCT) in patients with anorectal malformations.

Ninety patients with anorectal malformations (40 low and 50 high; median age, 7 years; range, 3 to 13) and twenty-five healthy children (median age, 8 years; range, 3 to 14 years) underwent measurement of TCT and SCT by the saturation technique. Ten radiopaque markers were ingested daily for 6 days followed by administration of a single abdominal x-ray on day 7. TCT in days was calculated by dividing the number of retained markers in the whole colon by the daily intake. SCT in four colonic segments (right, transverse, left, rectosigmoid) was described as a percentage of TCT (markers in one segment versus total number of retained markers). In high anomalies the degree of rectosigmoid dilatation was assessed by contrast enemas taken before closure of the stoma and later during follow-up.

TCT was significantly (P < .03) prolonged in patients with anorectal anomalies (median high, 2.1 days; low, 1.9 days versus 1.3 in healthy subjects). In patients with high anomalies right SCT was prolonged when compared with low anomalies and healthy subjects (median high, 24% versus low, 10% and normal subjects, 10%; P < .01). The impairment was more severe in patients with very high anomalies (P < .005). Patients with a low anomaly had prolonged rectosigmoid SCT (median low, 65% versus high, 43% and normal subjects, 49%; P < .05). Prolonged right colonic SCT and TCT correlated with symptomatic constipation in patients with high anomalies (P < .05) but not with those who had low anomalies. Impaired overall functional outcome correlated with prolonged right colonic SCT in patients with high anomalies and with prolonged rectosigmoid SCT in patients with low anomalies. There was no correlation between the degree of rectosigmoid dilatation and SCT or TCT.

Patients with anorectal malformations have abnormal colonic motility. The type of motility disorder in low anomalies is rectosigmoid hypomotility. In patients with high anomalies the motility disturbance is more generalized. The overall functional outcome was strongly related to the degree of these motility disorders.