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

Zhengzhou University

Status: Not yet enrolling

Conditions: Colonoscopy

Treatments: Drug: Endoscopic irrigation was performed using an aqueous suspension prepared with simethicone and normal saline.; Drug: Endoscopic irrigation was performed using a 0.1% menthol solution combined with simethicone.

Study type: Interventional

Funder types: Other

Identifiers

NCT07501962

2026-KY-0394-001

Details and patient eligibility

About

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.

Enrollment: 440 estimated patients

Sex: All

Ages: 18 to 75 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Diagnostic

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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440 participants in 2 patient groups, including a placebo group

Menthol group

Experimental group

Description:

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.

Treatment:

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

placebo group

Placebo Comparator group

Description:

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.

Treatment:

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