Tools for Practice

#45 Polyethylene Glycol (PEG) for Paediatric and Adult Chronic Constipation

How effective is Polyethylene Glycol (PEG) in paediatric and adult chronic constipation?

In adults and paediatric patients with chronic constipation, PEG is as or more effective than other agents. Compared to placebo, it relieves constipation in one in every 2-3 patients and adds 1-3 bowel movements per week. Maintenance treatment up to 24 weeks appears to be effective and safe in pediatric patients.

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At least ten systematic reviews of constipation with PEG versus other laxatives and/or placebo (range 5-25 trials, 594-2310 participants 2-52 weeks long):1-10
  • Adults outcomes, statistically significant:
    • PEG versus placebo:1,2,3,4
      • Relief of constipation: Number Needed to Treat (NNT)=2-3.
      • Increased stool frequency: 2-3 more per week.
    • PEG versus lactulose:3,5
      • Increased stool frequency by 1-2 more per week; reduced need for additional interventions.
  • Paediatrics outcomes, statistically significant:
    • PEG versus placebo:6,7
      • Increased stool frequency: 1.5 to 3 more per week.
    • PEG versus lactulose:5,6,7
      • Increased stool frequency: 0.7 to 1.5 more per week.
      • Increased likelihood of successful disimpaction: NNT 5
    • PEG versus milk of magnesia:7
      • Increase in stool frequency: 0.7 more per week.
    • Multiple outcomes improved such as resolved constipation, reduced abdominal pain, and reduced need for additional interventions.5,7
    • One review found no difference between PEG and other laxatives but excluded relevant studies.8
  • Other reviews found similar.9,10
RCTs have found similar efficacy to prucalopride11, superior efficacy to lactulose12 and efficacy in irritable bowel syndrome.13 Recent RCT of pediatric patients (n=115) compared maintenance PEG vs placebo13: successful treatment 67% vs 32% placebo, NNT 3 over 24 weeks; no significant adverse events   Context:
  • Chronic constipation impacts quality of life similar to diabetes and stable ulcerative colitis.15
  • Compared to lactulose, PEG may be better tolerated2 and is cost effective16 at approximately $1.00 per day (at 17 grams/day).
  • Although types of PEG vary in trials, this seems to have little impact on success.5,6
  • Current guidelines recommend PEG as the first line agent in paediatric17,18 and adult constipation.19
  • In reviews of multiple agents versus placebo, PEG has better evidence (versus senna or docusate)2 or better NNT (than psyllium or prucalopride).1,2
  • Dosing:
    • Adults, 17 grams daily.6
    • Paediatrics, 0.6 grams/kg/day (or 5-12 grams/day).6
      • Higher PEG doses (0.7 grams/kg/day) increases stool frequency over lower doses (0.3 grams/kg/day) by 1-2 more per week with no increase in adverse effects or fecal incontinence.5
    • Titrate doses to symptom relief and adverse events (diarrhea).
updated by sam nov 20, 2019

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  • G. Michael Allan MD CCFP
  • Michael R Kolber BSc MD CCFP MSc
  • Michelle Levy MD CCFP

1. Ford AC, Suares NC. Gut. 2011; 60(2):209-18.

2. Ramjumar D, Rao SS. Am J Gastroenterol. 2005; 100:936-71.

3. Belsey JD, Geraint M, Dixon TA. Int J Clin Practice 2010; 64 (7): 944-55.

4. Katelaris P, Naganathan V, Liu K, et al. BMC Gastroenterology 2016; 16: 42.

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6. Candy D, Belsey J. Arch Dis Child. 2009; 94(2):156-60.

7. Gordon M, MacDonald JK, Parker CE, et al. Cochrane Database Syst Rev. 2016; 8:CD009118.

8. Chen SL, Cai SR, Deng L, et al. Medicine (Baltimore). 2014; 93(16):e65.

9. Paré P, Fedorak RN. Can J Gastroenterol Hepatol. 2014; 28(10):549-57.

10. CADTH Rapid Response Report. Treatments for Constipation: A Review of Systematic Reviews [Internet]. Canadian Agency for Drugs and Technology in Health. Ottawa: ON. 2014 Nov. Available at: Accessed March 16, 2015

11. Treepongkaruna A, Simakachorn N, Pienvichit P, et al. BMC Pediatrics. 2014; 14:153.

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13. Chapman RW, Stanghellini V, Geraint M, et al. Am J Gasteroenterol. 2013; 108(9):1508-15.

14. Modin L, Walsted AM, Dalby K, et al. J Pediatr Gastroent Nutr 2018; 67(6):732-7.

15. Belsey J, Greenfield S, Candy D, et al. Aliment Pharmacol Ther. 2010; 31(9):938-49

16. Taylor RR, Guest JF. Aliment Pharmacol Ther. 2010; 31(2):302-12.

17. Bardisa-Ezcurra L, Ullman R, Gordon J, et al. BMJ. 2010; 340:c2585

18. Tabbers MM, DiLorenzo C, Berger MY, et al. JPGN. 2014; 58:258-74

19. Bharucha AE, Dorn SD, Lembo A, et al. Gastroenterology. 2013; 144(1):211-7.

Authors do not have any conflicts of interest to declare.