Treatment of Refractory Constipation

Recommended Treatment Algorithm

The American Gastroenterological Association (AGA) and the American College of Gastroenterology (ACG) recommend polyethylene glycol (PEG) as first-line therapy for refractory constipation, with a strong recommendation and moderate-quality evidence supporting its efficacy 1, 2, 3
PEG demonstrates durable response over 6 months, with common side effects including abdominal distension, loose stool, flatulence, and nausea, which are generally well-tolerated 1, 3
The AGA-ACG panel provides a strong recommendation for linaclotide in patients who do not respond to over-the-counter (OTC) agents, with a dosing regimen of 145 mcg orally once daily 4
Plecanatide receives a strong recommendation from the 2023 guidelines for chronic idiopathic constipation (CIC) management, as an alternative secretagogue with a similar mechanism to linaclotide 1, 2
Prucalopride receives a strong recommendation as a serotonin type 4 agonist for CIC, working through a different mechanism compared to osmotic/stimulant laxatives 1, 2

Bisacodyl receives a strong recommendation for short-term use (≤4 weeks) or rescue therapy, and can be combined with other pharmacological agents 3, 4
Senna receives a conditional recommendation with low-quality evidence, and trial doses should be started low and titrated 4

Magnesium-based products, such as milk of magnesia, are contraindicated in patients with creatinine clearance <20 mL/min due to the risk of hypermagnesemia 5
Sodium picosulfate/magnesium citrate is contraindicated in patients with congestive heart failure, hypermagnesemia, and severe renal impairment 6
Elderly patients (≥65 years) on sodium picosulfate have an increased risk of hyponatremia (absolute risk increase 0.05%) 6

The AGA and ACG recommend confirming adequate trial of current medications (milk of magnesia and sodium picosulfate) for at least 4 weeks before switching to PEG 3, 4
PEG is recommended as the next step due to its strong evidence base and cost-effectiveness 1, 3
If PEG is inadequate after 4-6 weeks, adding or switching to a prescription secretagogue (linaclotide or plecanatide) is recommended 1, 4
Prucalopride may be considered if secretagogues fail or are not tolerated 1, 2