Effect of a Novel Colonoscopic Lavage Solution on Colonoscopy Quality

Effect of a Novel Colonoscopic Lavage Solution on Colonoscopy Quality: A Randomized Controlled Trial Evaluating Efficacy and Safety

In recent years, with the continuous advancement of digestive endoscopy techniques, how to improve the adenoma detection rate (ADR) by optimizing endoscopic procedural details has become a research hotspot. Colonic spasm can lead to narrowing of the intestinal lumen, deepening of mucosal folds, and limited field of view, thereby affecting lesion exposure and reducing examination quality. Although traditional intravenous antispasmodic drugs (such as scopolamine) can alleviate intestinal spasms, they may cause side effects such as increased heart rate, blood pressure fluctuations, and other systemic adverse reactions. In contrast, menthol is a natural monoterpene compound derived from peppermint oil. It can inhibit L-type calcium channels on the cell membrane of smooth muscle through local application, thereby reducing intracellular calcium concentration and inducing smooth muscle relaxation. This helps to relieve intestinal spasms and patient discomfort during colonoscopy. On the other hand, simethicone, a commonly used defoaming agent, can reduce surface tension, eliminate foam, and improve mucosal visualization. Theoretically, combining antispasmodic menthol with defoaming simethicone may further optimize the visual field during colonoscopy and increase the ADR through a synergistic "antispasmodic + defoaming" mechanism. Therefore, this study plans to conduct a prospective randomized controlled trial to evaluate the antispasmodic effect, safety, and impact on the ADR of a novel irrigation solution (0.1% menthol combined with simethicone suspension) in colonoscopy, providing evidence-based medical support for optimizing endoscopic procedures.

Study Overview

• Status: Not yet recruiting
• Conditions: Colonoscopy
• Intervention / Treatment: Diagnostic test: Endoscopic irrigation was performed using a novel irrigation solution; Diagnostic test: Irrigation was performed endoscopically using normal saline.

• Study Type: Interventional
• Enrollment (Estimated): 498
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jianning Yao; Phone Number: 13733183434; Email: rjyy@zzu.edu.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

1. Age between 18 and 75 years, regardless of gender;
2. Scheduled to undergo colonoscopy (for screening, diagnostic, or follow-up purposes);
3. Adequate bowel preparation quality (Boston Bowel Preparation Scale score ≥ 6);
4. Voluntarily signed informed consent and able to cooperate with completing study-related assessments.

Exclusion Criteria:

1. Allergy to menthol, cyclodextrin, or related substances;
2. History of severe intestinal diseases (such as ulcerative colitis, Crohn's disease, intestinal perforation, intestinal obstruction, intestinal tumors, etc.);
3. Presence of severe dysfunction of vital organs such as the heart, liver, kidneys, or lungs, or coagulation disorders;
4. Pregnant or lactating women;
5. Use of anticholinergic drugs, calcium channel blockers, or other spasmolytic agents within one week prior to the examination;
6. Psychiatric disorders or cognitive impairment that prevent cooperation with the study;
7. History of contraindications to colonoscopy or serious adverse reactions during previous procedures.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Irrigation solution group; Endoscopic irrigation was performed using a novel irrigation solution (0.1% menthol solution combined with simethicone aqueous suspension). Preparation method: The solution was prepared using normal saline as the solvent. Menthol cyclodextrin inclusion complex (containing 7.3% menthol) was accurately weighed at 6.85 g and dissolved in 500 ml of normal saline to obtain a 0.1% menthol solution. After complete dissolution, 5 g of simethicone was added to prepare the aqueous suspension.	Diagnostic test: Endoscopic irrigation was performed using a novel irrigation solution; Endoscopic irrigation was performed using a novel irrigation solution (0.1% menthol solution combined with simethicone aqueous suspension).
Placebo Comparator: placebo group; Irrigation was performed endoscopically using normal saline.	Diagnostic test: Irrigation was performed endoscopically using normal saline.; Irrigation was performed endoscopically using normal saline.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adenoma detection rate (ADR).	ADR = (number of patients with at least one adenomatous polyp detected / total number of patients in the group) × 100%. Pathological diagnosis was used as the gold standard.	Day 0

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of intestinal spasm	The percentage of patients with an intestinal spasm score of 2 or 3 out of the total number of patients in the group. Intestinal spasm scoring criteria: Score 1 (Excellent): No spasm; the lumen opening is greater than or equal to two-thirds of the maximum diameter. Score 2 (Moderate): Moderate spasm; the lumen opening is less than two-thirds of the maximum diameter. Score 3 (Poor): Severe spasm; the oral-side lumen cannot be visualized. The maximum diameter is defined as the diameter of the intestinal lumen when fully distended.	Day 0
Spasm inhibition rate	The percentage of patients whose lumen opening exceeded two-thirds of the maximum diameter within 30 seconds after water injection irrigation, relative to the total number of patients in the group.	Day 0
Polyp detection rate (PDR)	PDR = (number of patients with at least one polyp detected / total number of patients in the group) × 100%.	Day 0

Collaborators and Investigators

• Sponsor: The First Affiliated Hospital of Zhengzhou University

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: March 18, 2026
• First Submitted That Met QC Criteria: March 24, 2026
• First Posted (Actual): March 30, 2026

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 24, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: 2026-KY-0395-001

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No