Anorectal Motility Abnormalities in Children with Encopresis and Chronic Constipation

ObjectiveTo evaluate the response to rectal distension in children with chronic constipation and children with chronic constipation and encopresis.Study designWe studied 27 children, aged 3 to 16 years, with chronic constipation; 12 had encopresis. Anorectal motility was measured with a solid state catheter. When the catheter was located in the internal sphincter, the balloon was inflated to 60 mL with air.ResultsThere were no differences in age, sex distribution, and duration of constipation in the two groups. Comparing groups, anorectal manometry showed no differences in the resting sphincter pressure, recovery pressure, the lowest relaxation pressure, and percent relaxation. However, time to maximum relaxation, time to recovery to baseline pressure, and duration of relaxation were significantly higher in patients with constipation and encopresis, compared with patients who had constipation alone.ConclusionsThere may be an imbalance in neuromuscular control of defecation in constipated patients with encopresis that results in incontinence as a consequence of the increased time to recovery and duration of relaxation of the internal anal sphincter.