Prevention of colonic spasm using L-menthol in colonoscopic examination.

Purpose: The detailed efficacy of intraluminal L-menthol for preventing colonic spasm is not known. The aim of this study was to evaluate the effectiveness of L-menthol in preventing colonic spasm during colonoscopy.
Methods: We analyzed 65 patients (mean age: 71.7 years; 49 men and 16 women) who were administered 0.8% L-menthol (MINCLEA, Nihon Seiyaku, Tokyo, Japan) intraluminally for severe colonic spasm during colonoscopic examination at Kyoto Prefectural University of Medicine between February 2012 and May 2013. The efficacy of L-menthol was defined as the absence of colonic spasm during a period of 30 s, and its effect was evaluated at 30 s, 1 min, and 5 min after administration. Additionally, various characteristics of these patients were analyzed. Twenty-seven patients with severe colonic spasm were administered intraluminal water and assessed as controls.
Results: L-Menthol was effective in preventing colonic spasms in 60.0%, 70.8%, and 46.5% of patients at 30 s, 1 min, and 5 min, respectively. In contrast, water was effective in 22.2%, 29.6%, and 48.1% of patients at 30 s, 1 min, and 5 min, respectively. There was a significant difference about the efficacy at 30 s and 1 min between L-menthol and water (P = 0.0009, P = 0.0006).
Conclusions: L-Menthol (0.8%) was effective in preventing colonic spasm during colonoscopic examination.