Table 2 IRR for colorectal and colon cancer according to BM frequency by sex

From: Bowel movement frequency and risk of colorectal cancer in a large cohort study of Japanese men and women

   Colorectal cancer Colon cancer
BM Observed person-years No. of cases Multivariate-adjusteda IRR 95% CIb No. of cases Multivariate-adjusteda IRR 95% CIb
Men
1per day 175 485 346 1.00   211 1.00  
 Every 2–3 days 18 335 30 0.77 0.53–1.12 11 0.46 0.25–0.85
 Every 4–5 days 1515 2 0.56 0.14–2.26 2 0.93 0.23–3.75
 Every 6 days or less 321 1 1.16 0.16–8.27 1 1.86 0.26–13.4
Women
1per day 196 472 204 1.00   155 1.00  
 Every 2–3 days 72 891 51 0.71 0.52–0.97 38 0.70 0.49–0.996
 Every 4–5 days 8937 10 1.12 0.59–2.11 7 1.01 0.47–2.17
 Every 6 days or less 1880 5 2.47 1.01–6.01 4 2.52 0.93–6.82
  1. IRR=incidence rate ratios; BM=bowel movement; BMI=body mass index.
  2. aAdjusted for age, BMI, intake frequency of green leafy vegetables, daily alcohol drinking, current smoking status, time spent for walking per day, family history of colorectal cancer and education.
  3. bCI: confidence interval.