INTRODUCTION:
Colonoscopy is the gold standard in the prevention and diagnosis of colorectal disease that relies on adequate bowel preparation for optimal visualization of the colonic mucosa. Glucagon-like Peptide 1 Receptor Agonists (GLP-1RAs), used for managing diabetes mellitus (DM), have emerged as highly effective and increasingly adopted weight-loss agents. GLP-1RAs influence gastrointestinal motility and may have implications for bowel preparation in colonoscopy. We aimed to describe the adequacy of bowel preparation between patients on GLP-1RAs at the time of colonoscopy versus those not on GLP-1RAs.

METHODS:
This is an IRB-approved retrospective observational study of patients who underwent colonoscopy at a single tertiary referral center between 2017 and the end of 2023. Patients were categorized based on their use of GLP-1RAs at the time of colonoscopy. Data was collected on patient demographics, GLP-1RAs medication, bowel preparation adequacy, and Boston Bowel Prep Scores (BBPS). Frequencies and percentages were described using measurements of central tendency. Differences between groups were assessed using Chi-squared or Fisher exact tests as appropriate.

RESULTS:
The study, which included 39,444 patients, examined the influence of GLP-1RAs on colonoscopy outcomes. Ninety-nine patients were on GLP-1RAs, and 39,345 patients were not. The GLP-1RAs group had a median age of 60 (IQR 54-66) years; the majority were female (65%) and white (63%). The cohort had a median BMI of 34.42 (IQR 30.2-39.4), with 76% categorized as obese and 88% being diabetic with a mean HbA1c of 7.57 (±1.96). None carried a diagnosis of gastroparesis; the majority were not on prokinetics or narcotic medications (Table 1). None of the patients omitted the GLP-1RA dose prior to the procedure. The primary indications for colonoscopy were predominantly screening (68%), followed by diagnostic (24%) and surveillance (8%). Bowel preparation adequacy was not significantly different between the non-GLP-1RAs and the GLP-1RAs group: 89.3% vs. 94.9% (p = 0.07). The total mean BBPS was slightly higher in the GLP-1RAs group compared to the non-GLP-1RAs group (7.76 vs. 7.30), although not statistically significant (p = 0.14) (Table 2).

CONCLUSION:
The use of GLP-1RAs is not associated with lower-quality bowel preparations and may be continued perioperatively. More studies using prospective controlled data are needed to validate our findings.

Table 1: Patient Demographics

Table 2: Indications and Bowel Preparation Quality Comparing non-GLP1-RAs to GLP-1RAs

Malcolm Chapman

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