[Comparison of the effectiveness and safety of polyethylene glycol with and without electrolytes in the treatment of chronic constipation].
INTRODUCTION
To compare the effectiveness and safety of polyethylene glycol with and without electrolytes (EL) over a 12 week period in treatment of chronic constipation in paediatrics.


MATERIAL AND METHODS
This was an observational, prospective, longitudinal, parallel group study, including 62 children with chronic constipation according to ROME III criteria and a history of faecal impaction. The children were divided into groups, one group of 30 received polyethylene glycol without EL (PEG) and 32 PEG with EL (PEG+EL) for at least 12 weeks. The main outcomes were the number of bowel movements at 6 and 12 weeks, and the presence of electrolyte disturbances at 6 weeks.


RESULTS
The mean weekly stool frequencies were similar in both groups at 6 and 12 weeks, with 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% (25 of 30) of the PEG group had at least one electrolyte disturbance compared with 56% (18 of 32) in the PEG+EL group (P=.02). Hyponatraemia was found in 15% (5 of 32) vs. 36% (11 of 30) of PEG+EL and PEG groups, respectively (P=.05). None of the laboratory abnormalities were clinically relevant.


CONCLUSIONS
PEG formulations with or without EL have a quite similar effectiveness, safety and acceptability. PEG without EL produced more electrolyte abnormalities, but none of them were symptomatic.