Constipation is a very common symptom and affects persons of all ages and both sexes.

Management of chronic constipation starts with patient education, review of medications and lifestyle modifications (increasing dietary fiber, physical activity and adequate hydration).

Patients are commonly initiated on fiber supplementation (bulk laxatives) as empiric therapy. If a patient fails empiric fiber therapy, osmotic agents are usually the next agent of choice due to their favorable safety profile, efficacy, ease of use and low cost.

Osmotic laxatives are now considered a first-line option in the management of patients with constipation.

Among the different types of osmotic laxatives that have been used in clinical practice are milk of magnesia (magnesium hydroxide), lactulose and polyethylene glycol (PEG).

PEG has been shown to be better than lactulose in relieving chronic constipation.

In a randomized, comparative trial, Attar et al compared the safety and efficacy of PEG solution with lactulose for the treatment of chronic idiopathic constipation. A total of 115 patients with chronic constipation were included in the trial and were randomly assigned to treatment with either PEG (n = 60) or lactulose (n = 55) for 4 weeks. Patients who were treated with PEG had a higher mean stool frequency when compared to that in the lactulose group; 1.3 vs 0.9 (p = 0.005), respectively.

A greater overall improvement was noted in the PEG group. At week 4, overall improvement was assessed on a visual analogue scale (VAS). The score ranged from 0, pointing to no change, to 10, suggesting excellent improvement. The mean VAS ratings for overall improvement were 7.4 in the PEG group vs 5.2 in the lactulose group (p < 0.001).

PEG was also better tolerated as compared to lactulose, PEG group had less flatus, bloating or abdominal pain. Hence, low-dose PEG+E is a safe and better alternative to lactulose in the treatment of patients with chronic constipation.

The study recommended that treatment with PEG should be initiated using 1 sachet/day, and the dose increased to 2 or 3 sachets/day if required.

Suggested Reading

1. Schiller LR. Chronic constipation: new insights, better outcomes? Lancet Gastroenterol Hepatol. 2019;4(11):873-82.
2. Liu LW. Chronic constipation: current treatment option. Can J Gastroenterol. 2011;25 Suppl B:

22B-28B.

3. Lacy BE. Update on the management of chronic idiopathic constipation. Am J Manag Care. 2019; 25(4 Suppl):S55-S62.
4. Ramkumar D, Rao SS. Efficacy and safety of traditional medical therapies for chronic constipation: systematic review. Am J Gastroenterol. 2005;100(4):936-71.
5. Attar A, Lémann M, Ferguson A, et al. Comparison of a low dose polyethylene glycol electrolyte solution with lactulose for treatment of chronic constipation. Gut. 1999;44(2):226-30.
6. Katelaris P, Naganathan V, Liu K, et al. Comparison of the effectiveness of polyethylene glycol with and without electrolytes in constipation: a systematic review and network meta-analysis. BMC Gastroenterol. 2016;16:42.