Rectal Cancer



Cancer is when cells in the body split without control or order. These cells go on to form a growth or tumor. The term cancer refers to harmful growths. These growths attack nearby tissues. They also spread to other parts of the body. It’s not clear exactly what causes these problems. It’s likely a mix of genes and the environment.

Risk Factors

Your chances are higher for:

  • Age 50 years and older
  • Being male
  • Inherited diseases such as familial adenomatous polyposis
  • Prior colon or rectal cancer, or polyps
  • Having certain genes
  • Colon or rectal cancer in your family—mainly with a parent, sibling, or child
  • Ulcerative colitis or Crohn disease
  • Obesity
  • Lifestyle factors such as:
    • Smoking
    • Diet high in red meat, and low in fruits, vegetables, and whole grains
    • Drinking excess alcohol
    • Little or no exercise

People of the Black race have the highest chance of getting and dying from colon and rectal cancers.



You may not notice any symptoms at first. When present, rectal cancer may cause:

  • Bleeding without other problems
  • A change in bowel habits
  • Blood in the stool that is either bright red, or black and tarry
  • Pain or pressure
  • Feeling of a mass
  • Itching
  • Belly pain
  • Weight loss
  • Feeling tired
  • Breathing problems and pale skin—signs of anemia


The doctor will ask about your symptoms and health history. Your answers and a physical exam may point to rectal cancer. You may also have:

  • A digital rectal exam—the doctor will feel for lumps with a lubricated, gloved finger in the rectum
  • Blood tests
  • Endoscopy such as:
    • Colonoscopy
    • Sigmoidoscopy
  • Imaging tests such as:
    • CT scan
    • CT colonography
    • MRI scan
    • Transrectal ultrasound
    • Barium enema
    • PET/CT scan
  • Biopsy —Tissue samples are tested in a lab (done during endoscopy)

The exam and your test results will help find out the stage of cancer you have. Staging guides your treatment. Rectal cancer is staged from 0-4. Stage 0 is a very localized cancer. Stage 4 is a spread to other parts of the body



Rectal cancer is treated with more than one method. Sometimes they’re combined. This can be done with:


Surgery is the main way to treat rectal cancer. There are many ways this can be done. It depends on where the cancer is and how much it has spread.

  • Polypectomy and local excision—Cancer is removed during endoscopy.
  • Local transanal resection—A border of healthy tissue along with the cancer is removed.
  • Transanal endoscopic microsurgery (TEM)—A border of healthy tissue along with the cancer is removed. The hole in the wall is sewn back together.
  • Low anterior resection—A border of healthy tissue along with the cancer is removed.
  • Proctectomy—The rectum is removed. The end of the colon and the anal canal are attached. Bowel use will stay.
  • Abdominoperineal resection—The rectum, anal canal, and surrounding tissue are removed.
  • Pelvic exenteration—Removal of rectum, anal canal, and nearby organs with cancer. This may include the prostate, uterus, or bladder.

A colostomy is a path for solid waste to pass from the body is made through the belly wall. A special bag is needed to collect the waste. This may be needed for some procedures on the rectum.

If the bladder is removed, you will need a urostomy . This is a path for urine to pass out of the body through the belly wall. Some, but not all types, need a bag to collect the waste.

Radiation Therapy

Radiation therapy is the use of radiation to kill cancer cells and shrink tumors. It’s aimed at the tumor from a source outside the body. It may also be given at the same time as chemotherapy.


Chemotherapy is the use of drugs to kill cancer cells. It may given by mouth, shots, or IV. The drugs enter the bloodstream and travel throughout the body.


Targeted Therapy

These medicines block tumors from growing and spreading. It may be used with other methods. In many cases, these medicines aren’t used until cancer is in later stages.

Other Medicines

Some medicines are part of treatment. Others may help control side effects. These may include:

  • Corticosteroids
  • Medicines to make more red or white blood cells
  • Anti-nausea medicines
  • Pain relievers



The purpose of these tests is find and treat cancer early. If you are aged 50 years and older, and are not at high risk, talk to your doctor to find the right test for you:

  • Colonoscopy—every 10 years
  • Sigmoidoscopy—every 5-10 years
  • CT colonography—every 5 years
  • Barium enema—every 5 years
  • Stool DNA test every 3 years
  • Fecal occult blood test (FOBT)—every year
  • Fecal immunochemical test (FIT)—every year

Talk to your doctor about testing after age 40 if you are Black, Asian, or a native of Alaska.

Talk to your doctor about how often you should be tested if you have:

  • People in your family with colon or rectal cancer, or polyps
  • People in your family with inherited diseases of the colon or rectum
  • Or had colon or rectal cancer, polyps
  • Inflammatory bowel diseases

Lifestyle Changes

To help lower your chances of colon cancer:

  • Quit smoking—your doctor will help you find the best way.
  • Eat a well-balanced, healthful diet.
  • Get at least 30 minutes of activity a day on most days of the week.
  • Alcohol—Don’t drink more than 2 a day if you’re a man or more than 1 a day if you’re a woman.
  • Keep a healthy weight.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.