Polyethylene glycol 3350 for constipation in children with dysfunctional elimination

Children with daytime wetting often have constipation, and treatment of constipation helps children become dry. Polyethylene glycol 3350 (Miralax, Braintree Laboratories, Braintree, Massachusetts) is a nonaddictive, tasteless powder that can be mixed with any liquid for treatment of constipation.

We review our use of polyethylene glycol 3350 in 35 girls and 11 boys with dysfunctional elimination. Noninvasive urodynamic studies and post-void residual measurement were performed before and during treatment.

A significant increase in frequency of bowel movements occurred while taking polyethylene glycol 3350 (p = 0.0001). Average final dose was 0.63 gm/kg. The only reported adverse effect was diarrhea (9 patients). Of the children 18 became dry, 26 had decreased wetting and 2 had no improvement. Voided volume increased (146 vs 210 ml, p <0.0001) and post-void residual decreased significantly (92 vs 48 ml, p <0.0001) while on polyethylene glycol 3350. Ten children were still considered constipated including both patients who experienced no change in wetting. Average final dose in this group (0.69 gm/kg) did not differ significantly from those in whom constipation resolved (0.61 gm/kg). Patients in whom constipation resolved had a significantly lower post-void residual than those who remained constipated (11.8% vs 30.6%, p <0.01) and were significantly more likely to become dry or improved (p = 0.045).

The efficacy, compliance and lack of significant side effects make polyethylene glycol 3350 an ideal substance for treatment of constipation in children with dysfunctional elimination. Persistent constipation was associated with decreased resolution of voiding symptoms and significantly increased post-void residuals.