Constipation and colorectal cancer risk: the Fukuoka Colorectal Cancer Study.

Constipation has been suspected to be linked to colorectal cancer risk, but epidemiological evidence is inconclusive. We described the prevalence of constipation and related lifestyle factors in a community and examined the relation of constipation and other bowel habits to colorectal cancer risk. The prevalence study was based on 833 community controls in the Fukuoka Colorectal Cancer Study, and 212 cases of Dukes' stage A were used in a study on bowel habits and colorectal cancer risk. Bowel habits were assessed by in-person interview. Odds ratio (OR) and 95% confidence interval (CI) of colorectal cancer were estimated with adjustment for dietary and nondietary factors. Constipation was reported by 10.3% of men and 27.7% of women. Individuals with less frequent bowel movements had a lower intake of total energy and were physically less active. The multivariate-adjusted OR (95% CI) of colorectal cancer were 1.51 (1.02-2.25) for self-reported constipation, 1.60 (1.05-2.44) for functional constipation, and 1.24 (0.81-1.90) for infrequent bowel movements (<1 stool/day). Self-reported constipation was fairly common in Japanese adults. Constipation was associated with a moderately increased risk of colorectal cancer.