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Rectal Cancer

The Causes, Symptoms, Treatment and Prevention of Rectal Cancer


Updated May 20, 2014

Rectal cancer is a type of cancer that develops in the rectum, the last six inches of our large intestine. Like other organs in our body, the rectum is vulnerable to many diseases and conditions, such as cancer.

Causes and Risk Factors of Rectal Cancer

We can't exactly pinpoint what causes rectal cancer, but we know what may increase our risk of developing it. Risk factors for rectal cancer include:
  • being older than 50
  • family or personal history of colon cancer (a person does not need a family history of colon cancer to have rectal cancer; it is most commonly diagnosed in those without a family history.)
  • personal history of polyps(small growths in the colon)
  • smoking

Rectal Cancer Symptoms

In the early stages, rectal cancer usually doesn't have symptoms. As the disease progresses, which can take years, symptoms include:
  • blood in stool
  • persistent constipation, diarrhea or other bowel changes
  • thinner stools
  • unexplained weight loss
  • abdominal pain, tenderness, cramping or discomfort
  • fatigue
These rectal cancer symptoms are not unique and can also be symptoms of many other conditions.

Rectal Cancer Screening

Several colon cancer screening methods are highly effective at detecting rectal cancer as well. Colon and rectal cancer screening tests include:

Colonoscopy. A colonoscopy allows the doctor to get an in-depth view of the colon with a colonoscope, a fiber optic tube that is attached to a microscopic camera that transmits live video to a monitor. The colonoscope is gently inserted in to the anus and slowly to the colon, giving the doctor a full view of the rectum and large intestine.

Sigmoidoscopy. Much like a colonoscopy, a sigmoidoscopy is done with a flexible lighted tube with an attached camera, but it is limited to only the lower part of the colon.

Barium Enema. During a barium enema, a doctor inserts liquid barium in to the rectum. X-rays are taken of you laying in several positions. The barium allows the colon to be viewed better on x-rays.

  • What to Expect During a Barium Enema
  • Illustration: How a Barium Enema Works

  • Fecal Occult Blood Test. A fecal occult blood test (FOBT) finds blood in your stool that you may not see with the naked eye or confirms that it is actually blood in the stool that you may have seen. You are given a special kit to collect stool samples.

  • What to Expect when Having a Fecal Occult Blood Test

  • For adults who are at the average risk of colon and rectal cancer, it is recommended to begin screening at age 50. Adults who are classified at a higher risk may begin screening earlier at the recommendation of their doctor. Remember that even if you are not experiencing symptoms of rectal cancer, you should always follow your doctor's screening recommendations.

    Diagnosing Rectal Cancer

    If a screening test reveals suspicious results, then a colon biopsy is done. A biopsy can be done during a colonoscopy or surgically. During a biopsy, small amounts of rectal tissue are removed and then sent to a pathology lab to screen for evidence of cancer. If cancer is present, then the stage of rectal cancer is then determined through surgery to remove the cancer. Surrounding lymph nodes are tested and may also be removed during the surgery.

    Treatment of Rectal Cancer

    In the early stages of rectal cancer, surgery may be the only treatment needed. There are several surgical methods used to to remove cancerous rectal tissue. The type of surgery chosen depends on general health, stage of rectal cancer and location of the tumor. For those who are not good candidates for surgery, radiation therapy may be an option but will not be as effective.

    Chemotherapy is also a common treatment method for rectal cancer. The organs in our body are made up of cells that divide and multiply as the body needs them. When these cells continue to multiply unnecessarily, the result is a mass or growth, also called a "tumor." Chemotherapy drugs work by eliminating these rapidly multiplying renegade cells.

    Chemotherapy for rectal cancer may be prescribed before or after surgery and may also be given in conjunction with radiation therapy.

    Radiation therapy is another treatment method used to treat rectal cancer. This type of therapy uses certain types of high-energy radiation beams to shrink tumors or eliminate cancer cells. Radiation therapy works by damaging a cancer cell's DNA, making it unable to multiply.

    In cases of rectal cancer, radiation therapy may be given prior to surgery to help shrink large tumors. It may also be given in conjunction with chemotherapy.

    Colon Cancer Prevention

    Regular colon cancer screening is key to preventing rectal cancer. Screening can identify precancerous growths before they potentially progress into cancer. Keep in mind that it takes years for rectal cancer to develop, so routine screening can detect these changes before they turn cancerous. Remember, for average risk people, colon cancer screening should begin at age 50.

    Avoiding risk factors for rectal cancer can also reduce your risk of developing the disease. Eating a balanced diet, not smoking and maintaining a healthy weight are all ways to reduce your risk of not only rectal cancer, but many other conditions as well.


    Detailed Guide: Colon and Rectum Cancer: What Are the Risk Factors for Colorectal Cancer? American Cancer Society. 7 Mar. 2006. 04 July 2008.

    Overview: Colon and Rectum Cancer: What Causes Colorectal Cancer? American Cancer Society. 15 Mar. 2006. 04 July 2008.

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