The purpose of a recent study published in Anales de Pediatria was to compare effectiveness and safety of polyethylene glycol (PEG) with and without electrolytes (E) in the treatment pediatric patients with chronic constipation.

This was an observational, prospective, longitudinal, parallel group study, which was conducted over a 12-week period. The study recruited 62 children with chronic constipation determined by the ROME III criteria, who had a history of fecal impaction. The children were divided into two groups - 30 patients received PEG without electrolytes and 32 were given PEG with electrolytes (PEG+E), for at least 12 weeks.

The findings showed that the mean weekly stool frequencies were equivalent between the groups at 6 and 12 weeks - 5.4 and 4.6 stools per week in the PEG+EL and PEG groups, respectively, at 12 weeks. After 6 weeks of treatment, 83% children in the PEG group had at least one electrolyte disturbance compared with 56% in the PEG+EL group. Meanwhile, hyponatremia was 15% versus 36% in PEG+E and PEG groups, respectively. All laboratory abnormalities were clinically irrelevant.

From the results, it was inferred that PEG formulations with or without electrolytes have comparable effectiveness, safety, and acceptability. Although asymptomatic, PEG without electrolytes produced more electrolyte abnormalities in children with constipation than PEG+E.