Tests for Colorectal Cancer

Colon Basics

Getting the Names Right
The colon is sometimes referred to as the large intestine. It begins at the end of the small intestine and ends at the rectum. The rectum is at the far end of the colon and leads to the anus where feces leaves the body. The colon is responsible for excreting waste, maintaining fluid balance and processing minerals and vitamins.

Cancers in this area of the body are very common. Among cancers that both men and women get, colorectal cancer is the second leading cause of cancer death in the United States. Lung cancer is the first.

Polyps and Cancer

Cancers in the colon usually begin as polyps. Most people with polyps do not know they have them and it may take years for polyps to become cancers. If polyps are removed before they become cancerous, colon cancer is prevented. If cancers are removed when they are small, the chance of being cured is much higher.


Screening colonoscopies are recommended starting at age fifty. The exam itself is usually not very memorable because of medications given to help people relax. Many sleep through their procedure and have no memory of it at all.

During the exam, a narrow tube with a tiny camera and light is inserted through the anus and threaded up through the rectum and colon. The doctor looks for polyps and cancers. Polyps are removed and abnormal looking tissue is sampled (biopsied). Some people have minor discomfort during the procedure.

The part of having a colonoscopy people dread is the prep starting a day or two before the procedure. Taking unpleasant medication is bad enough, but the cramping and diarrhea that follow for many is hard to endure. It can be miserable but having a cleaned-out colon will help your doctor be able to spot polyps and cancers.

Other Tests

There are other ways to test for colon cancer. Some doctors test for tiny amounts of blood in the stool which can be a sign of cancer. This test is called a fecal occult blood test or fecal immunochemical test. A sample for this test is usually collected at home. If blood is found, then further testing is ordered. This test is often coupled with sigmoidoscopy-an examination of the sigmoid (lower part of colon).

For more information about colorectal cancer visit the following sites:

Updated 3/8/16
Inside diagram
Colonoscopy Procedure