A study published in the Anales de Pediatria aimed to compare the effectiveness and safety of polyethylene glycol with and without electrolytes (EL) over a 12 week period, in treating chronic constipation in pediatric patients.

This observational, prospective, longitudinal, parallel group study, recruited 62 children diagnosed with chronic constipation, according to the ROME III criteria, having a history of fecal impaction. Among these, 30 children were given polyethylene glycol without EL (PEG), whereas 32 received PEG with EL (PEG+EL), for at least 12 weeks.

The results revealed that the mean weekly stool frequencies were comparable in both the groups at six and 12 weeks, with 5.4 and 4.6 stools per week in the PEG+EL and PEG groups at 12 weeks, respectively. However, after six weeks of treatment, 83% of the children in the PEG group had at least one electrolyte disturbance compared to only 56% in the PEG+EL group. While hyponatremia was found in 15% and 36% of the patients in PEG+EL and PEG groups, respectively. Yet, these laboratory abnormalities were clinically asymptomatic.

Hence, it was inferred that although effectiveness, safety, and acceptability of PEG formulations with or without EL are similar, PEG without EL produces more electrolyte abnormalities when compared to PEG with EL.