Epidemiology of large bowel cancer.

Results from epidemiologic studies have provided insights into the etiology of large bowel cancer. Markedly diverse incidences of colorectal cancer exist in various parts of the world and within different regions of a given country. Studies of migrant populations have revealed a role for environmental factors, particularly dietary, in the etiology of colorectal cancers. Genetic factors and inflammatory bowel disease also place certain individuals at increased risk. Sedentary lifestyle, cholecystectomy, and ureterosigmoidostomy may also increase the risk of developing large bowel cancer.