Effect of Intraluminal Administration of Menthol Solution During Colonoscopy on Colonic Spasm and Adenoma Detection Rate

NCT07501962 | Not Yet Recruiting DMC

• 1 other identifier: 2026-KY-0394-001
• Study Type: interventional
• Target: 440
• Locations: 0 countries
• Sites: N/A

Brief Summary

In recent years, with increasing research into antispasmodic agents, topical antispasmodics have attracted considerable attention due to their direct action on the gastrointestinal mucosa and relatively low incidence of adverse reactions. Menthol, a natural terpenoid compound found in peppermint oil, has been confirmed by numerous studies to possess spasmolytic properties. Existing evidence indicates that menthol relaxes intestinal smooth muscle and alleviates spasm symptoms by antagonizing L-type calcium channels on the smooth muscle cell membrane, thereby reducing calcium influx. Furthermore, it exhibits local analgesic effects and can attenuate visceral hypersensitivity. Some studies suggest that oral or topical administration of peppermint oil preparations may improve intestinal spasm during colonoscopy, highlighting its potential utility in digestive endoscopy procedures. Nevertheless, current research on the spasmolytic efficacy and safety of menthol solution when administered via endoscopic irrigation during colonoscopy remains limited, and high-quality clinical trials are urgently needed for validation. This study aims to investigate the effectiveness and safety of menthol solution in relieving intestinal spasm, thereby providing scientific evidence for optimizing colonoscopy procedures.

Conditions

Colonoscopy

Outcome Measures

Primary Outcomes (2)

• Incidence of intestinal spasm

  Intestinal spasm score: 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. Spasm incidence: The percentage of patients with an intestinal spasm score of 2 or 3 out of the total number of patients in the group.

  Day 0

• 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 Outcomes (2)

• Spasm inhibition rate

  Day 0

• Polyp detection rate (PDR)

  Day 0

Study Arms (2)

Menthol group

EXPERIMENTAL

Endoscopic irrigation was performed using a 0.1% menthol solution combined with simethicone. Preparation method: Normal saline was used 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 prepare a 0.1% menthol solution. After complete dissolution, 5 g of simethicone was added to form an aqueous suspension.

Drug: Endoscopic irrigation was performed using a 0.1% menthol solution combined with simethicone.

placebo group

PLACEBO COMPARATOR

Endoscopic irrigation was performed using an aqueous suspension prepared with simethicone and normal saline. Preparation method: 5 g of simethicone was added to 500 ml of normal saline to form the aqueous suspension.

Drug: Endoscopic irrigation was performed using an aqueous suspension prepared with simethicone and normal saline.

Interventions

Endoscopic irrigation was performed using a 0.1% menthol solution combined with simethicone. DRUG

Preparation method: Normal saline was used 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 prepare a 0.1% menthol solution. After complete dissolution, 5 g of simethicone was added to form an aqueous suspension.

Menthol group

Endoscopic irrigation was performed using an aqueous suspension prepared with simethicone and normal saline. DRUG

Preparation method: 5 g of simethicone was added to 500 ml of normal saline to form the aqueous suspension.

placebo group

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

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

Sponsors & Collaborators

• The First Affiliated Hospital of Zhengzhou University: lead

MeSH Terms

Interventions

Simethicone; Saline Solution

Intervention Hierarchy (Ancestors)

Dimethylpolysiloxanes; Silicones; Siloxanes; Organosilicon Compounds; Organic Chemicals; Polymers; Macromolecular Substances; Biomedical and Dental Materials; Manufactured Materials; Technology, Industry, and Agriculture; Crystalloid Solutions; Isotonic Solutions; Solutions; Pharmaceutical Preparations

Central Study Contacts

Jianning Yao

CONTACT

13733183434; rjyy@zzu.edu.cn

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Chief Physician

Study Record Dates

• First Submitted: March 18, 2026
• First Posted: March 30, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: March 30, 2026

Record last verified: 2026-03