Should tirzepatide (Zepbound) be discontinued two weeks before a colonoscopy?

Does Zepbound Need to Be Stopped 2 Weeks Prior to Colonoscopy?

There is no established requirement to stop Zepbound (tirzepatide) 2 weeks before colonoscopy, but emerging evidence suggests GLP-1 receptor agonists may impair bowel preparation quality and delay gastric emptying, warranting consideration of discontinuation 1 week prior for weekly formulations.

The Core Issue: Delayed Gastric Emptying vs. Bowel Preparation

The question conflates two separate concerns that require different management approaches:

1. Aspiration Risk from Delayed Gastric Emptying

Recent multidisciplinary consensus guidelines 1 address GLP-1 receptor agonists (which includes tirzepatide as a dual GIP/GLP-1 agonist) in the peri-operative setting. The American Society of Anesthesiologists initially recommended stopping these medications either the day before (for daily dosing) or one week before (for weekly injections) to minimize aspiration risk. However, tirzepatide has a 5-day elimination half-life 1, meaning stopping it just 2-3 days before may be insufficient to fully restore normal gastric emptying.

Key consideration: Multiple case reports document regurgitation and aspiration in patients on GLP-1 agonists despite prolonged fasting (up to 20 hours) 2. One case specifically involved tirzepatide where gastric secretions and undigested food were found despite appropriate fasting 2.

2. Bowel Preparation Quality

More critically for colonoscopy outcomes, recent research demonstrates that GLP-1 receptor agonist use significantly impairs bowel preparation quality 3. In a 2024 study of 446 patients:

• Mean Boston Bowel Preparation Scale (BBPS) scores were significantly lower in patients actively taking GLP-1 RAs (7.0 vs 7.5, p=0.046)
• Patients on GLP-1 RAs had 2.3 times higher rate of inadequate preparation (BBPS <5: 15.5% vs 6.6%, p=0.01)
• Repeat colonoscopy due to poor preparation was required 70% more often (18.9% vs 11.1%, p=0.041) 3

A case report specifically documented that a patient on tirzepatide required 2 months of discontinuation before achieving successful upper endoscopy after multiple failed attempts due to food residues 4.

Evidence-Based Recommendation Algorithm

For colonoscopy specifically:

1. If colonoscopy is elective/screening: Consider stopping tirzepatide 1 week (7 days) before the procedure to allow for drug clearance (approximately 1.5 half-lives) and improved bowel preparation quality

2. If urgent/semi-urgent colonoscopy:

   • Proceed with colonoscopy but inform the endoscopist and anesthesiologist
   • Consider enhanced bowel preparation regimen (split-dose preferred) 5
   • Plan for possible repeat procedure if preparation inadequate
   • Use rapid sequence intubation if general anesthesia required

3. Timing considerations:

   • The 2025 US Multi-Society Task Force guidelines emphasize that bowel preparation should be completed at least 2 hours before procedure start 5
   • This addresses aspiration risk from the bowel prep itself, not the tirzepatide

Critical Caveats

The "2-week" timeframe mentioned in your question is not evidence-based. However:

• Standard 1-week discontinuation may be insufficient given tirzepatide's 5-day half-life and documented cases requiring longer discontinuation 4
• No high-quality studies specifically define optimal discontinuation timing for tirzepatide before colonoscopy
• The 2025 colonoscopy preparation guidelines [5-5] do not specifically address GLP-1 agonists, as this is emerging evidence

Weigh the risks: Stopping tirzepatide causes:

• Loss of glycemic control in diabetic patients
• Potential weight regain
• Interruption of cardiovascular benefits 6

Practical Clinical Approach

For a patient on weekly tirzepatide scheduled for colonoscopy:

• Minimum: Hold the dose scheduled within 7 days of the procedure
• Optimal: Hold for 7-10 days if feasible (skip 1-2 doses for weekly formulation)
• Communicate clearly with the endoscopy team about medication use
• Use split-dose bowel preparation (strongest recommendation from guidelines) 5
• Consider same-day preparation only for afternoon procedures 5
• Monitor for inadequate preparation and counsel patient about possible repeat procedure

The evidence strongly suggests that continuing tirzepatide through colonoscopy preparation significantly increases the risk of inadequate bowel preparation and need for repeat procedures, which carries its own morbidity and cost implications 3.