Colon (anatomy)

In the gastrointestinal system, the colon is the "segment of large intestine between the cecum and the rectum. It includes the ascending colon, the transverse colon, the descending colon, and the sigmoid colon."

There are many disorders of the colon, and colorectal cancer is a serious one. In the U.S., there were an estimated 108,070 new case of colon and 40,740 rectal cancer in 2008, with 49,760 deaths for the combined colorectal category. Early detection and treatment improves the chance of successful treatment; the best screening methods are still the subject of investigation. They range from noninvasive testing of feces for blood, and various direct viewing techniques, using a flexible optical sigmoidoscope or more intrusive colonoscope.

Risk factors probably include some genetic predisposition. A low-fat, high fiber may have a role, but the data are inconclusive. There has been evidence that aspirin and other non-steroidal anti-inflammatory drugs may have a role in prevention. Some of the selective cyclooxygenase 2 inhibitors may have even stronger preventive effect, but these also carry significant cardiovascular risk and probably cannot be justified for preventive use.