The small intestine has a greater cell mass than the colon, it is longer and with greater surface area and has a faster rate of epithelial turnover. At first, this might suggest that the small bowel epithelium could be at greater risk of the cumulative genetic errors that predispose to cancer. However, the incidence of cancer of the small bowel is more than tenfold lower than that of colorectal cancer.The small intestine has a greater cell mass than the colon, it is longer and with greater surface area and has a faster rate of epithelial turnover. At first, this might suggest that the small bowel epithelium could be at greater risk of the cumulative genetic errors that predispose to cancer. However, the incidence of cancer of the small bowel is more than tenfold lower than that of colorectal cancer.