Colon & Rectal Cancers


The colon and rectum form the large bowel. The colon is the upper 5 to 6 feet. The rectum is the last 6 to 8 inches. When abnormal cells grow in the colon, a cancerous tumor may form. Colon tumors grow slowly. They may get big and block the bowel.


Signs & Symptoms

Colon and rectal cancers can occur without clear symptoms. For this reason, screening is important. When symptoms occur, they include:

•  A change in bowel habits for 2 or more weeks or constipation or diarrhea for 1 or more weeks.

•  Frequent gas pains, cramps, bloating, or feelings of fullness in the abdomen

•  Red or dark blood in or on the stool or rectal bleeding. Pencil thin stools.

•  Fatigue and/or iron deficiency anemia in men and older women

•  A feeling that the bowel does not empty completely

•  Weight loss for no known reason

Illustration of colon and rectum.

Causes, Risk Factors & Care

Risk factors for colon and rectal cancers:

•  Polyps (benign growths that can become cancerous over time). Most colon and rectal cancers develop from polyps.

•  Family history of colon or rectal cancer. Unless it is treated, an inherited condition called Familial Polyposis puts a person at a very high risk.

•  Having ulcerative colitis or Crohn’s disease.

•  Aging. Colon and rectal cancers occur most often in people over age 50.

•  Smoking. Heavy alcohol use.

•  Eating a diet high in animal fat and low in fiber

•  Lack of exercise and/or being very overweight

Finding and treating the cancer early is vital. Treatment includes surgery, chemotherapy, and radiation therapy.


The National Cancer Institute

800.4.CANCER (422-6237)


The American Cancer Society


Self-Care / Prevention


•  Schedule and go to follow-up exams.

•  Join a cancer support group.

•  Follow a high fiber, low-fat diet. Eat whole-grain breads and cereals. Have at least 5 servings of vegetables and fruits a day.


Colon and rectal cancers are completely curable if found early. Have screening tests as advised by your doctor.

•  High-sensitivity fecal occult blood test

•  Flexible sigmoidoscopy

•  Colonoscopy

How often testing needs to be done depends on the test(s) given. {Note: If you have a family history of colon polyps or colon or rectal cancers, screening tests may need to be started sooner than age 50.}

•  Have colon polyps removed.

•  Eat plenty of fruits, vegetables, and whole grains. Limit fat.

When to Seek Medical Care

Contact Doctor When:

•  You have any symptoms of colon and rectal cancer listed on this page.

•  You need to schedule screening tests for colon and rectal cancer. Follow the schedule your doctor advises.

This website is not meant to substitute for expert medical advice or treatment. Follow your doctor’s or health care provider’s advice if it differs from what is given in this guide.


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