Bowel Regimen for Mounjaro (Tirzepatide)-Induced Constipation

First-Line Approach

The American College of Gastroenterology recommends initiating polyethylene glycol (PEG) 17 grams once daily as the primary pharmacologic agent for tirzepatide-induced constipation, with the goal of achieving one non-forced bowel movement every 1-2 days 1, 2
Increasing fluid intake, particularly in patients with low daily consumption, is recommended to help manage constipation 1, 3
Regular physical activity is encouraged to utilize the gastrocolic reflex and help manage constipation 1, 3

Adding a stimulant laxative, such as bisacodyl 5-10 mg once daily, to the PEG regimen is recommended rather than switching agents 1, 2
Alternative osmotic agents, including lactulose, magnesium hydroxide, or magnesium citrate, can be considered if PEG is not tolerated 1, 4

Stool softeners (docusate) should not be used alone as they lack efficacy as monotherapy 1, 2
Fiber supplementation should not be added without ensuring adequate fluid intake, as this can worsen constipation 1
PEG should not be limited to 7 days in chronic constipation, as it can be used long-term safely 1

Prophylactic laxatives should be considered at the time of tirzepatide initiation in patients with pre-existing constipation or risk factors 2, 3

If constipation persists despite treatment, reassess for medication-induced causes beyond tirzepatide and evaluate for metabolic causes, including hypothyroidism, hypercalcemia, or hypokalemia 1, 3
Consider abdominal imaging to exclude mechanical obstruction or severe fecal loading 3
Refer to gastroenterology for consideration of newer agents, such as linaclotide or lubiprostone, if standard therapy fails 5, 6