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.