How to Self Screen for Colon Cancer

Co-authored by Joshua Ellenhorn, MD

Colon cancer is the third most common cancer. However, there are excellent screening tests available and, when caught early, colon cancer is able to be treated and cured in 90% of all cases.^{[1]
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Trustworthy Source
State of Massachusetts
Official website for the State of Massachusetts
Go to source} This is why following through with the recommended screening is so important. See your family doctor to learn how to self-screen for colon cancer via the at-home stool test, which is recommended every one to two years for people over the age of 50. Though colon screenings performed by trained doctors are always best, an at-home test is better than nothing and could point out issues that you'll need to address.

Method 1

Method 1 of 2:

Performing The At-Home Stool Test

1
Evaluate your level of risk for colon cancer. Everyone is eligible for colon cancer screening beginning at the age of 50; however, if you have a family history of colon cancer, or a personal history of inflammatory bowel disease (such as Crohn's disease or ulcerative colitis, both of which increase your risk of developing colon cancer) you may be eligible to begin screening earlier.^{[2]
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Expert Source

Joshua Ellenhorn, MD
Board Certified General Surgeon & Surgical Oncologist
Expert Interview. 28 April 2020.} Don't wait to discuss this with your doctor — even if you are still young, it is important to notify your doctor if you have any risk factors.
- See your doctor at age 50 to begin self-screening, and earlier if you believe you have additional risk factors (in which case your doctor will let you know at what age you are eligible to begin).
2
Obtain the testing package. The first thing you will need to do in order to self-screen for colon cancer is to obtain the at-home stool testing package. You will need to visit your family doctor to obtain this, and she will explain the procedure to you during this visit as well.
- One stool test is called the Fecal Occult Blood Test (FOBT). This looks for blood in your stool that is not visible to the naked eye. It is the most commonly used self-screening test for colon cancer.^{[3]
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  National Cancer Institute
  An agency in the National Institutes of Health focused on cancer research and patient support
  Go to source}
- Another stool test option is called the Fecal Immunochemical Test (FIT). This is almost the same as FOBT, except instead of detecting blood via heme it detects it via antibodies directed at human hemoglobin.^{[4]
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  Trustworthy Source
  National Cancer Institute
  An agency in the National Institutes of Health focused on cancer research and patient support
  Go to source}
- The final self-screening stool test option is called Cologuard. This evaluates both for the presence of blood in the stool, as well as for DNA that has been correlated to a higher risk for colon cancer.^{[5]
  X
  Trustworthy Source
  National Cancer Institute
  An agency in the National Institutes of Health focused on cancer research and patient support
  Go to source} It is quite new and therefore not currently recommended as the standard of care; however, studies indicate that the new Cologuard test could potentially have a greater ability to detect colon cancer than either the FOBT or the FIT tests.
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3
Collect the required number of stool samples. Once you have the package at home with you, you are ready to begin testing at the time of your next bowel movement. Take note of how many stool samples you will need. Some self-screening packages request three samples, often each the size of a smear on a piece of toilet paper. Others ask for only one sample, but it may require the whole bowel movement to be packaged and sent into the lab.
- One way to collect bowel samples more easily is to place a piece of plastic wrap over the toilet bowl, allowing it to hang just above the water level.
- After your bowel movement, you can then collect the stool sample (in the required amount) before flushing the rest down the toilet.
- Ensure that no urine contaminates your stool sample.
4
Store the stool sample at room temperature. It is important to store your stool sample at room temperature until you have a chance to return it to the lab. This should be done within seven days following the collection of your stool sample.
5
Send the stool sample back to the lab. After you have collected your sample and placed it in the appropriate areas of the packaging, you will need to return it to the lab for analysis. The address of the lab should be listed on the side of the package — normally, you can return it to any medical lab in your area, or to the hospital lab, whichever is most convenient for you to get to.
6
Book a follow-up appointment to review your results.^{[6]
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Research source} After the lab has finished analyzing your stool, you will want to go in to see your family doctor again to review the results of your stool test. Depending on whether the result is positive (suspicious for possible colon cancer) or negative (not worrisome), your doctor will help you to plan your next steps, if any further investigative steps need to be taken.

Method 2

Method 2 of 2:

Following Up With Your Results

1
Take comfort if you receive a negative result.^{[7]
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Trustworthy Source
State of Massachusetts
Official website for the State of Massachusetts
Go to source} If the result of your stool test comes back as negative for blood (or DNA), you can take confidence in knowing that your risk of colon cancer at this time is very low. Of course, no test is perfect, so there is always the slight possibility of a testing error, but more likely than not you are not at risk. Your doctor will advise you to proceed with your life as normal. No further testing will be indicated at this time.
- The stool test is generally repeated every one to two years for people 50 and older, in order to ensure regular screening.^{[8]
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- Make a note to yourself to follow up with your family doctor again at this time for a repeat stool test.
2
Proceed with a colonoscopy if you receive a positive result.^{[9]
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Research source} If the result of your stool test comes back positive, you will need to proceed with further investigations at this time. The next step is a colonoscopy, which is where a tube is inserted through the anus all the way up your colon so that your doctor can directly visualize the walls of the colon and look for any suspicious lesions or polyps.^{[10]
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Expert Source

Joshua Ellenhorn, MD
Board Certified General Surgeon & Surgical Oncologist
Expert Interview. 28 April 2020.} If there are any, these can be biopsied at the time of the test and evaluated under the microscope for the presence of cancer.^{[11]
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Trustworthy Source
American Cancer Society
Nonprofit devoted to promoting cancer research, education, and support
Go to source}
- If your colonoscopy shows nothing suspicious, you are in the clear and safe to go on with life as normal.
- If your colonoscopy reveals colon cancer, you will need to consult a medical oncologist (a cancer specialist) about how best to treat you colon cancer.
3
Understand that a positive stool test (the self-screening test for colon cancer) does not necessarily mean you have cancer.^{[12]
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Research source} It is important not to get overly worried about a screening test. This is because the purpose of the screening test is not to diagnose cancer, but rather, to figure out who is at a higher risk and as such needs to have a colonoscopy (which is the official diagnostic test).
- If you test positive for blood in your stool, there is a chance that you have colon cancer, but it is not diagnostic.
- If possible, try not to worry too much until you have followed through with the actual colonoscopy.
- Also, the good news is that, if you receive regular screening, colon cancer can be caught early in the stages where it can be treated and cured (90% of colon cancers caught early are able to be cured).^{[13]
  X
  Expert Source
  
  Joshua Ellenhorn, MD
  Board Certified General Surgeon & Surgical Oncologist
  Expert Interview. 28 April 2020.}

Expert Q&A
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Question

What is the best way to test for colon cancer?

Joshua Ellenhorn, MD
Board Certified General Surgeon & Surgical Oncologist
Joshua Ellenhorn, MD, is a board certified surgeon with advanced training in the fields of surgical oncology, minimally invasive surgery, and robotic surgery. He runs a private practice at Cedars-Sinai Medical Center in Los Angeles, California and is a nationally recognized leader in surgery, cancer research, and surgical education. Dr. Ellenhorn has trained more than 60 surgical oncologists and has spent over 18 years in practice at the City of Hope National Medical Center, where he was a professor and the chief of the Division of General and Oncologic Surgery. Dr. Ellenhorn performs the following surgical procedures: gallbladder surgery, hernia repair, colorectal cancer, skin cancer and melanoma, gastric cancer, and pancreatic cancer. He earned an MD from the Boston University School of Medicine, completed fellowships at the University of Chicago and Memorial Sloan-Kettering Cancer Center and finished his residency in surgery at the University of Cincinnati.

Joshua Ellenhorn, MD

Board Certified General Surgeon & Surgical Oncologist

Expert Answer

Support wikiHow by unlocking this expert answer.

One of the best ways to check for colon cancer is getting regular colonoscopies so you can detect polyps early.
Question

How do I lower my risk for colon cancer?

Gary Hoffman, MD
Colorectal Surgeon
Dr. Gary Hoffman is a board certified Colorectal Surgeon and the Clinical Chief of the Division of Colon and Rectal Surgery at Cedars Sinai Medical Center. With over 35 years of experience, Dr. Hoffman has helped to advance laparoscopic and robotic surgery for the treatment of colon and rectal cancer. Dr. Hoffman holds a BS from the University of California, Irvine, and a Doctor of Medicine (MD) from Vanderbilt University. He completed his surgical internship at Los Angeles County-USC Medical Center and his surgical residency at Louisiana State University-Charity Hospital of New Orleans Medical Center. Dr. Hoffman is an Attending Surgeon in the Division of General Surgery and Colon and Rectal Surgery at Cedars Sinai Medical Center. He is also an Associate Clinical Professor of Surgery at The David Geffen School of Medicine, University of California, Los Angeles. Dr. Hoffman is a member of The American Society of Colon and Rectal Surgeons, The Southern California Society of Colon and Rectal Surgeons, The American College of Surgeons, and The American Medical Association.

Gary Hoffman, MD

Colorectal Surgeon

Expert Answer

Support wikiHow by unlocking this expert answer.

Early screening and paying attention to your body are the two best things you can do to prevent colon cancer. Have a colonoscopy done at age 45, or sooner if you have risk factors like a family history of colon cancer.