Background and study aim: During bowel preparation for colonoscopy, stools transition from solid to watery. In Japanese culture, toilets typically offer large and small flush options. This study aimed to evaluate whether encouraging the use of small flushes for watery stools could reduce water consumption. Patients and methods: This single-center prospective observational study included a total of 220 patients undergoing colonoscopy. Over ten months, 111 patients who received standard instructions was included in non-intentional water (NW) group during early-period before intervention, while 109 patients who received interventional infographic poster promoting small flushes in the GREEN-Water (GW) group during late-period. Results: The GW group showed significantly lower median total water usage for bowel preparation (31.5 L 27.9–39.6) than the NW group (35.0 L 30.4–44.6, p < 0.005), suggesting a reduction of approximately 3.5 L per single colonoscopy. No significant differences were observed in fluid intake or bowel cleansing quality. Conclusions: The educational poster intervention promoting appropriate flush selection during bowel preparation may be a simple option for reducing water consumption, leading to green endoscopy.
Imagawa et al. (Thu,) studied this question.