Colon cancer

Diagnosing colorectal cancer

Fecal occult test
The fecal occult test is a valuable diagnostic tool for detecting colorectal cancer. The test picks up small amounts of blood in the stool. If positive, it indicates that something in the digestive tract may need further investigation. You can have this test done in your physician's office. If you need a physician experienced in diagnosing cancer, try Yale-New Haven Health Physician Referral Online.

Digital rectal exam
Sometimes lumps in the colon can be felt during a digital rectal exam (DRE). While not as sensitive as the fecal occult test, the exam is still useful in feeling tumors that may be growing. If you are 50 or older, you should have this digital exam done every year by your primary care physician.

Sigmoidoscopy or colonoscopy
During a sigmoidoscopy, your physician uses a miniature scope inserted into the lower part of the bowel to examine the inside of last part of the colon for growths or abnormalities. Small growths, called polyps, can be removed quickly and without major surgery. Since polyps can become cancerous over time, removing them is the most important step in preventing the development of colon cancer. Removed polyps are tested to see if they are benign or malignant (cancerous).

A colonoscopy is essentially the same procedure, except the doctor uses longer tube to exam the entire colon.

Lower GI series
During this test, the patient is first given an enema containing barium. Then X-rays are taken, with the barium highlighting the inside of the colon. Sometimes air can be carefully inserted into the colon, making small lesions easier to see. This is called a double contrast barium enema. Only a double contrast barium enema is sensitive enough to be used for screening.

Ultrasound
Ultrasound uses high-frequency sound waves to create an image of a part of the body. Your doctor may also perform a test called an endorectal ultrasound. A probe is inserted into the rectum to determine how large the tumor is, and whether it has spread. Tumors can require further testing through surgical biopsy.

Surgical biopsy
Surgical biopsies are performed under general anesthesia at the hospital or in your doctor's office. Surgeons remove a sample of tissue from a tumor and send it to the pathologists for examination. Sometimes, if the lump is small enough, the surgeon can remove it completely during this procedure.

Yale-New Haven patients who need a surgical biopsy for colorectal cancer can be seen as outpatients in the Ambulatory Care Center at the Temple Medical Building, 60 Temple St., New Haven (directions to Temple Medical Building).

See also:

Questions to ask before cancer tests

Cancer Services home page

Treating Colorectal Cancer
Online physician referral service

Last revised: May 1, 2007 (dh)

Home page URL: http://www.ynhh.org

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