Colorectal Cancer

If your doctor thinks you may have colorectal cancer, he or she will ask you questions about your Reference medical history and give you a physical exam. Other tests may include:

• A Reference colonoscopy, a test in which your doctor uses a lighted scope to view the inside of your entire colon. A colonoscopy may be done to look into symptoms such as unexplained bleeding from the rectum, constant diarrhea or constipation, blood in the stool, or pain in the lower abdomen. A colonoscopy is recommended when another screening test shows you may have colorectal cancer.^{Reference 4}
• A Reference sigmoidoscopy, a test in which your doctor uses a lighted scope to view the lower part of your intestine. A sigmoidoscopy may be done to look into symptoms such as unexplained bleeding from the rectum, constant diarrhea or constipation, blood in the stool, or pain in the lower abdomen. Doctors can also remove polyps during this test.
• A Reference barium enema, in which a whitish liquid with barium is inserted through your rectum into your intestine. The barium outlines the inside of the colon so that it can be seen on an X-ray.
• A Reference biopsy Opens New Window, in which a sample of tissue is taken from the inside of your intestine and examined under a microscope. A doctor called a Reference pathologist Opens New Window can look at the tissue sample and see if it contains cancer.
• A Reference complete blood count, which is a blood test. It is used to look into symptoms such as fatigue, weakness, anemia, bruising, or weight loss.

For people who have an increased risk for colorectal cancer, regular colonoscopy is the recommended screening test. It allows your doctor to remove polyps (polypectomy) and take tissue samples at the same time.

When you are diagnosed with colorectal cancer, your doctor may order other tests to find out whether the cancer has spread. These tests include:

• A Reference CT scan to see if the cancer has spread to your liver, lungs, or abdomen.
• A Reference chest X-ray to see if the cancer has spread to your lungs.
• An Reference MRI or Reference PET scan to see if the cancer has spread into your chest or organs in the abdomen or pelvis.
• An Reference ultrasound Opens New Window to find the cause of belly pain or increased belly girth or to see if the cancer has spread to your liver. An Reference endoscopic ultrasound Opens New Window is used to see how far rectal cancer may have spread.
• A Reference blood chemistry panel to see if the cancer has spread to your liver and bones.
• A Reference carcinoembryonic antigen (CEA) blood test to check the level of this Reference tumor marker Opens New Window.

Early detection

Colorectal cancer has a much better chance of being successfully treated when it is found early. Most people who get colorectal cancer are older than 50 and have no other risk factors besides their age.

Reference Routine screening can reduce deaths from colorectal cancer. Some screening tests find and remove polyps before they can turn into cancer. Other screening tests look for early signs of cancer, because that is when treatment works better. Screening methods include:

• Stool tests, such as the Reference fecal occult blood test (FOBT), the fecal immunochemical test (FIT), and the stool DNA test (sDNA).
• Reference Sigmoidoscopy.
• Reference Colonoscopy.
• Computed tomographic colonography (CTC), also known as Reference virtual colonoscopy.

Stool tests look for signs of cancer. If used as recommended, these tests may find cancer early, when treatment works better. Sigmoidoscopy and colonoscopy are tests that find and remove polyps to stop them from turning into cancer. Virtual colonoscopy finds polyps. With stool tests and virtual colonoscopy, if there are abnormal findings, you will need to have a colonoscopy to remove any polyps.

Talk to your doctor about which test is right for you. People with a higher risk for colorectal cancer, such as African Americans and people with a strong family history of colon cancer, may need to begin routine testing before age 50 and have it more often.

If you have a very strong Reference family history Opens New Window of colon cancer, you may want to talk to your doctor or a Reference genetic counselor Opens New Window about having a blood test to look for changed genes. Reference Genetic testing can tell you whether you carry a changed, or mutated, gene that can cause colon cancer. Having certain genes greatly increases your risk of colon cancer. But most cases of colon cancer are not caused by changed genes.

Opens New Window Colon Cancer: Which Screening Test Should I Have? Opens New Window

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This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Reference Terms of Use. Reference How this information was developed to help you make better health decisions.