Developing a Colonoscopy Preparation Protocol for Patients With Diabetes

Patients with diabetes have less effective colonoscopy preparation when compared to nondiabetic patients. This leads to the possibility of missed polyps, longer procedural time and patient dissatisfaction. Furthermore, the peri-colonoscopy period has been associated with increased risk of hypoglycemic events given the required change in diet and possible changes in antihyperglycemic medication regime, though this area is not well studied.

Studies have found that same day preparation for colonoscopy allowed for comparable bowel visualization to split dosing. Pairing this with a low fiber diet permitted the day prior to colonoscopy, the extent of changes to routine and diet within a patient with diabetes day for colonoscopy preparation is minimized and could reduce risk of side effects and hypoglycemia, while also ensuring adequate bowel preparation.

This study tests the hypothesis that creating a diabetic specific protocol (permitting a low fibre diet the day prior to colonoscopy and using same day preparation) will result in fewer hypoglycemic events and more adequate quality preparation in comparison to a conventional 2L PEG split day preparation with dietary restrictions in patients with diabetes.

Study Overview

• Status: Not yet recruiting
• Conditions: Diabete Mellitus; Hypoglycaemia; Colonoscopy (Ambulatory Patients)
• Intervention / Treatment: Other: timing of cleansing and procedure

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Lawrence Hookey, MD; Phone Number: 2292 613 544 3400; Email: lawrence.hookey@kingstonhsc.ca
• Study Contact Backup: Name: Amani Khan, MD; Phone Number: 647 628 9700; Email: amani.khan@kingstonhsc.ca

Study Locations

• Canada
  • Ontario
    • Kingston, Ontario, Canada, K7L 2V7
      • Kingston Health Sciences Centre
      • Contact: KHSC Hotel Dieu Colonoscopy Suite; Phone Number: 613-548-2342; Email: PatientRelations@KingstonHSC.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Patients Age over the age of 18
2. Able to read and understand the English language
3. Confirmed diagnosis of diabetes (Type 1 or Type 2)

Exclusion Criteria:

1. Patients without diabetes
2. Patients with prior hospital admission due to hypoglycemic events
3. Patients who have inflammatory bowel disease
4. Patients with ileus or bowel obstruction
5. Patients with history of colorectal resection
6. Patients receiving combined upper and lower endoscopies
7. Patients with ascites
8. Patients with previously documented severe renal impairment
9. Unable to provide consent
10. Pregnant or lactating female (females of child-bearing potential will undergo urine pregnancy testing)
11. Patients who have had a recent myocardial infarction(<6months)
12. Allergy to product ingredients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control Group (Standard Preparation); Participants will follow a clear-liquid diet after breakfast on the day before colonoscopy. They will ingest 2L of PEG at 7:00 PM the evening before the procedure and the remaining 2L four hours prior to colonoscopy.	Other: timing of cleansing and procedure; we are altering the timing of colonoscopy and cleansing for colonoscopy for patients with diabetes.
Experimental: Diabetes-Specific Protocol Group; Participants will follow a four-day, low-fiber carbohydrate diet. They will be allowed to consume dinner up until 7:00 PM the night before the colonoscopy. On the day of the procedure, they will ingest 2L of PEG between 5:00 AM and 6:00 AM and the remaining 2L between 8:00 AM and 9:00 AM.	Other: timing of cleansing and procedure; we are altering the timing of colonoscopy and cleansing for colonoscopy for patients with diabetes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Bowel Preparation	Primary outcome is the proportion of patients achieving an adequate bowel preparation, defined as a Boston bowel preparation scale (BBPS) score of 6 or greater, with no section scoring below 2 . The scale ranges from 0-9, with 9 being the best possible score.	During colonoscopy

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Glucose Monitoring	Evaluating the incidence of hypoglycemic events (blood glucose <3.9 mmol/L) from the initiation of bowel preparation until discharge from colonoscopy suite.	Pericolonoscopy period
Patient Rating	Patient-reported ratings of convenience, tolerability and adverse events associated with the preparation protocol.	Pericolonoscopy period

Collaborators and Investigators

• Sponsor: Queen's University

Publications and helpful links

General Publications

• Tong Y, Huang JQ, Chen Y, Tu M, Wang W. Impact of glucagon-like peptide 1 receptor agonist liraglutide and dipeptidyl peptidase-4 inhibitor sitagliptin on bowel cleaning and gastrointestinal symptoms in type 2 diabetes. Front Pharmacol 2023;14:1176206.
• Alvarez-Gonzalez MA, Flores-Le Roux JA, Seoane A, Pedro-Botet J, Carot L, Fernandez-Clotet A, Raga A, Pantaleon MA, Barranco L, Bory F, Lorenzo-Zuñiga V. Efficacy of a multifactorial strategy for bowel preparation in diabetic patients undergoing colonoscopy: a randomized trial. Endoscopy. 2016 Nov;48(11):1003-1009. doi: 10.1055/s-0042-111320. Epub 2016 Aug 4. PMID: 27490086.
• Seo M, Gweon TG, Huh CW, Ji JS, Choi H. Comparison of bowel cleansing efficacy, safety, bowel movement kinetics, and patient tolerability of same-day and split-dose bowel preparation using 4 L of polyethylene glycol: a prospective randomized study. Dis Colon Rectum. 2019;62(12):1518-27.
• International Hypoglycaemia Study Group. Hypoglycaemia, cardiovascular disease, and mortality in diabetes: epidemiology, pathogenesis, and management [published correction appears in Lancet Diabetes Endocrinol. 2019 Jun;7(6):e18]. Lancet Diabetes Endocrinol. 2019;7(5):385-396. doi: 10.1016/S2213-8587(18)30315-2
• Alexandra Chirila, Mary E Nguyen, Jill Tinmouth, Ilana J Halperin, Preparing for Colonoscopy in People with Diabetes: A Review with Suggestions for Clinical Practice, Journal of the Canadian Association of Gastroenterology, Volume 6, Issue 1, February 2023, Pages 26-36
• Patient Characteristics Associated With Quality of Colonoscopy Preparation: A Systematic Review and Meta-analysis. Gandhi K, Tofani C, Sokach C, Patel D, Kastenberg D, Daskalakis C. Clin Gastroenterol Hepatol. 2018 Mar;16(3):357-369.e10. doi: 10.1016/j.cgh.2017.08.016. Epub 2017 Aug 18.
• Chung YW, Han DS, Park KH, Kim KO, Park CH, Hahn T, et al. Patient factors predictive of inadequate bowel preparation using polyethylene glycol: a prospective study in Korea. Journal of Clinical Gastroenterology. 2009;43(5):448-52. doi: 10.1097/MCG.0b013e3181662442 18978506.
• Taylor C., Schubert M. L. (2001). Decreased efficacy of polyethylene glycol lavage solution (Golytely) in the preparation of diabetic patients for outpatient colonoscopy: A prospective and blinded study. American Journal of Gastroenterology, 96(3), 710-714.
• Nguyen DL, Jamal MM, Nguyen ET, Puli SR, Bechtold ML. Low-residue versus clear liquid diet before colonoscopy: a meta- analysis of randomized, controlled trials. Gastrointest Endosc. 2016 Mar;83(3):499-507.e1. doi: 10.1016/j.gie.2015.09.045. Epub 2015 Oct 13. PMID: 26460222.

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2028
• Study Completion (Estimated): June 1, 2028

Study Registration Dates

• First Submitted: April 6, 2026
• First Submitted That Met QC Criteria: April 6, 2026
• First Posted (Actual): April 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: glucose monitoring; bowel preparation; diabetes protocol
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Nutritional and Metabolic Diseases; Hypoglycemia; Diabetes Mellitus
• Other Study ID Numbers: 20253698; 3698 (Other Grant/Funding Number: PSI)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No