Epidemiology Bowel movement frequency and risk of colorectal cancer in a large cohort study of Japanese men and women M Kojima1, K Wakai2,3, S Tokudome1, K Tamakoshi4, H Toyoshima4, Y Watanabe5, N Hayakawa6, K Suzuki7, S Hashimoto8, Y Ito7 and A Tamakoshi3 for the JACC Study Group 1Department of Health Promotion and Preventive Medicine, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan 2Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan 3Department of Preventive Medicine/Biostatistics and Medical Decision Making, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan 4Department of Public Health/Health Information Dynamics, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan 5Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan 6Department of Epidemiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-8553, Japan 7Department of Public Health, Fujita Health University School of Health Sciences, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan 8Department of Hygiene, Fujita Health University School of Medicine, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan Correspondence to: M Kojima, E-mail: masayok@med.nagoya-cu.ac.jp The relationship between bowel movement (BM) frequency and the risk of colorectal cancer was examined in a large cohort of 25 731 men and 37 198 women living in 24 communities in Japan. At enrollment, each participant completed a self-administrated questionnaire on BM frequency and laxative use. Incidence rate ratios (IRR) with 95% confidence intervals (CI) were estimated using Cox's proportional-hazard model. During the follow-up period (average length 7.6 years), 649 cases of colorectal cancer, including 429 cases of colon cancer, were identified. Among women, subjects who reported a BM every 2-3 days had the lowest risk of developing colorectal (IRR=0.71, 95% CI=0.52-0.97) and colon cancer (IRR=0.70, 95% CI=0.49-1.00), whereas those reporting a BM every 6 days or less had an increased risk of developing colorectal (IRR=2.47, 95% CI=1.01-6.01) and colon cancer (IRR=2.52, 95% CI=0.93-6.82) compared with those reporting 1 BM per day. A similar, but nonsignificant, association between the frequency of BM and cancer risk was observed in men. There was no association between colorectal or colon cancer risk and laxative use. Regulating BM frequency might therefore have a role in the prevention of colorectal cancer. British Journal of Cancer (2004) 90, 1397-1401. doi:10.1038/sj.bjc.6601735 Published online 9 March 2004 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.