Management of Chronic Constipation with Polyethylene Glycol

Introduction to Treatment

The American Gastroenterological Association recommends polyethylene glycol (PEG) as first-line pharmacological therapy for chronic idiopathic constipation, with proven efficacy and safety for up to 6 months of continuous use 1

The American Gastroenterological Association suggests starting with PEG 17g once daily mixed in 8 ounces of liquid as the primary osmotic laxative for chronic constipation 1, 2
PEG can be initiated either after a trial of fiber supplementation or used in combination with fiber from the outset, with consideration of psyllium first for patients with low dietary fiber intake 1, 3

The 2023 AGA-ACG guidelines provide a strong recommendation with moderate certainty of evidence for PEG use in chronic idiopathic constipation 1, 2
PEG increases complete spontaneous bowel movements by 2.90 per week compared to placebo (95% CI 2.12-3.68) 3
PEG increases spontaneous bowel movements by 2.30 per week compared to placebo (95% CI 1.55-3.06) 3
Treatment response rate is 3.13 times higher with PEG versus placebo (RR 3.13, 95% CI 2.00-4.89) 3

The standard dose of 17g once daily is FDA-approved and proven effective for chronic constipation 2
PEG can be taken with or without electrolytes, with studies showing efficacy with both formulations 2
Common adverse effects include abdominal distension, loose stools, flatulence, and nausea, but no significant differences in serious adverse events compared to placebo 1, 3, 4

PEG demonstrates similar or greater efficacy than prucalopride and lactulose in head-to-head trials 2
PEG is more cost-effective and accessible than prescription secretagogues or prokinetics 3
For refractory cases, consider prescription secretagogues like linaclotide or plecanatide, or prokinetic agents like prucalopride, with strong recommendations and moderate certainty 5

Evaluate for dyssynergic defecation with anorectal manometry and balloon expulsion testing, and perform colonic transit study to differentiate slow-transit constipation from outlet obstruction 6
Identify and address constipating medications and rule out metabolic causes like TSH, calcium, or glucose abnormalities 6