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."

Epidemiology

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.

Risk factors for colon disease

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.

Early detection of abnormalities

Early detection and treatment improves the chance of successful treatment; the best screening and diagnostic 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.

The role of promising new gastrointestinal imaging techniques, such as a single-use miniaturized camera that is swallowed, transmits to viewers outside the body, and such as computerized tomography, with and without contrast agents, is still not firmly established. The noninvasive methods clearly are more comfortable and generally have lower risk, but they cannot provide biopsy material, or early-interventional surgical removal of suspicious tissue.