colon

The colon is an approximately 5- to 6-foot long tube that connects the small intestine to the rectum. The colon—which along with the rectum is called the large intestine—moves and processes digesting food across your body and down towards the rectum, where it exits the body as stool. There are several parts of the colon, including:

Ascending colon: This section is where undigested food begins its journey through the colon. Undigested food moves upwards through this section, where fluid is reabsorbed more efficiently.

Transverse colon: Moving across the body, the transverse colon takes the food from one side of the body to the other (right to left).

Descending colon: Once the food has travelled across the top through the transverse colon, it makes its way downward through the descending colon—typically on the left side.

Sigmoid colon: The final section of the colon, this portion is shaped like an “S” and it is the last stop before the rectum.

All of the body's cells normally grow, divide, and then die in order to keep the body healthy and functioning properly. Sometimes this process gets out of control. Cells keep growing and dividing even when they are supposed to die. When the cells lining the colon and rectum multiply uncontrolled, colorectal cancer may ultimately develop.

Fortunately, most colorectal cancers begin as small precancerous (adenomatous or serrated) polyps. These polyps usually grow slowly and do not cause symptoms until they become large or cancerous. This allows the opportunity for detection and removal at this pre-cancerous polyp stage before the development of cancer.