Effectiveness of Polyethylene Glycol 3350 versus Lactulose in Management of Functional Constipation in Children

Introduction: Constipation is one of the common problems in childhood. Recently, Polyethylene Glycol (PEG 3350) has been suggested as a good alternative laxative to Lactulose as a treatment option in pediatric constipation. The current study aimed to compare the efficacy of two laxatives (PEG 3350 and Lactulose) in the management of functional constipation and evaluate the side effects. Methods and materials: In an open-label clinical trial, 1-13 year-old children with functional constipation according to ROME IV criteria and the presence of RAIR based on anorectal manometry were studied. The patients were randomized to receive either PEG3350 (0.8 g/kg/d) or Lactulose (2 ml/kg/d). Both groups received the medication orally in two divided doses for 12 weeks. They were evaluated clinically at the end of 4, 8, and 12 weeks of therapy, and the end of 16 and 20 weeks from enrolment. At the end of the 12th week, Success was defined as a defecation frequency ≥ 3/week and improvement in stool consistency without painful defecation, as well as encopresis ≤ 1 every two weeks. Results: We enrolled 43 patients (M20, F23) aged 4.16 ± 2.3 years. At the end of the 12th week, good clinical outcomes were achieved in 95% (PEG) and 77.3% (Lactulose). The PEG group had a significant increase in defecations in a week compared with the Lactulose group (6.26 ± 0.5 vs. 4.94 ± 0.8, p = 0.0001) and a significant decrease in encopresis (35% vs. 10, p = 0.01). PEG achieved defecation without pain (0% vs. 22.7%) and less hard stools (5% vs. 18.2%, p = 0.1). Patients reported less abdominal pain and bloating than children using Lactulose (25% and 0% vs. 68.2% and 27.3%, respectively). We reported a significant relapse because of sudden ceasession of treatment in the Lactulose group (13.6% vs. 5%, p = 0.04) compared with the PEG group. Conclusion: PEG3350 compared with Lactulose provided a higher success rate, less relapse rate, and fewer side effects in the treatment of constipated children.