Step by Step At Home Colon Cancer Screening

Table of Contents

    The fourth leading cause of death worldwide is colorectal cancer – a highly treatable disease if caught early. The loss of life due to colorectal cancer has prompted physicians and public health officials to promote screening as a method of finding colorectal cancer early. Recent efforts by the CDC and WHO have helped to significantly drop the number of colorectal cancer deaths due to a widespread push in the healthcare system for colon cancer screening. 

    While colonoscopies are the preferred form of screening, many physicians will opt to prescribe home cancer screening kits for colorectal cancer for their patients who are reluctant to endure a colonoscopy. 

    If your doctor has ordered you to take an at home colon cancer screening test, this article will help to inform you step-by-step on the procedure. You will also learn who receives and interprets the cancer screening  results as well as what those results mean for you in terms of future screenings. 

    What Happens During an At Home Cancer Screening: Detailed Step By Step Breakdown

    There are three at home colorectal screening kits available by prescription. These include the FIT, FOBT (or gFOBT), and Cologuard™ kits. While all three kits ask you to provide a stool sample to be mailed off to a lab for analysis, each has distinct steps that must be followed in the directions. Below, each of these three tests are broken down step-by-step so you have a clear understanding of what to expect once you receive your kit. 

    The following guidelines are not meant to be taken as instructions but are for informative use only. Only follow the directions provided within the kit and as directed by your healthcare provider. 

    FIT (Fecal Immunochemical Test)

    This test checks your stool sample for microscopic amounts of blood that can be an indication that you have colorectal cancer or precancerous polyps. You do not need to change your diet or stop taking medications before this test. You also do not need to cleanse your bowels. 

    Each FIT kit contains the following:

    • Privacy notice and FIT instructions
    • 1 folded stool collection paper
    • 1 plastic bag with absorbent material
    • 1 FIT tube
    • 1 pre-paid return envelope


    1. Check the thin side of the FIT tube to make sure your date of birth and your name are correct. 
    2. Write the date on the tube in designated space. 
    3. If you have to, urinate and flush the toilet
    4. Unfold the collection paper and place it in the toilet floating on top of the water. 

    During procedure

    1. Sit on the toilet
    2. Defecate on the paper. 
    3. Open tube by twisting and lifting the cap.
    4. Use the grooved end of the stick to scrape stool until grooves are covered.
    5. Place the stick with the stool sample into the FIT tube. 
    6. Snap the FIT tube to close. 


    1. Flush toilet with remaining stool and collection paper. 
    2. Place the FIT tube with your stool sample into the plastic bag with absorbent material.
    3. Do not remove absorbent material and seal the bag.
    4. Place the plastic bag into the provided pre-paid and pre-addressed return envelope. 

    Return your test within two days of doing it, by mail or dropped off to your healthcare provider. If you have any questions, call your physician to clarify directions or confusion about the test itself. 

    Lab results

    The lab will send the results of your test directly to your physician who will contact you to discuss the results. If your doctor suspects that you may have received a false positive or false negative test you will probably be asked to repeat the test. 

    Negative result. If there is no blood test detected in your stool sample your fecal immunochemical test is considered negative. Your doctor may recommend that you repeat the test every year if you are at risk for colon cancer. 

    Positive result. A positive result means that you have abnormal bleeding somewhere in your colon. Remember that several diseases can cause abnormal bleeding in your colon, including colon cancer, polyps, and hemorrhoids. In this case, your physician will most likely advise you to schedule a colonoscopy to find the source of bleeding.

    FOBT (Fecal Occult Blood Test)

    This test checks your stool for occult blood, or blood you cannot see by looking at your stool. In this test, you need to collect stool samples for 3 consecutive days. The reason for this is to increase the possibility of finding blood, as the bleeding may not be occuring every day. The FOBT does have food, supplement, and medication restrictions. Three days before your sample collection, do not eat or drink the following:

    • Raw fruits and veggies
    • Red meat, like liver, lamb, or beef
    • Vitamin C supplements more than 250 mg
    • Fruit with vitamin C added
    • Antacids
    • Anti-diarrhea medications
    • Iron supplements
    • Vitamin E
    • NSAIDs (nonsteroidal anti-inflammatory drugs)

    The FOBT kit usually contains the following:

    • Hemoccult™ slide (card that collects sample)
    • Applicator stick
    • Container to collect stool sample
    • Return envelope

    The following directions should be repeated three times before mailing or dropping off completed FOBT test:


    1. Using a pen, write your age, name, and address on the front of the slide.
    2. Fill in the date you are collecting your stool sample.
    3. If you have to urinate, do so. 
    4. Flush the toilet and let water fill back up again. 


    1. Open flap of Hemoccult slide.
    2. Sit on the toilet like you normally do to have a bowel movement.
    3. Use the clean, dry container to catch your stool before it touches the water.
    4. Collect a sample of your stool using one end of the applicator stick.
    5. Thinly smear the sample inside the square (usually marked with “A”).
    6. Throw away the stick into the trash.


    1. Close the cover of the Hemoccult slide.
    2. Place slide into the provided envelope.
    3. Do not place the Hemoccult slide into a plastic bag.
    4. Empty container with remaining stool into the toilet. 
    5. Flush the toilet. 
    6. Wash your hands thoroughly. 

    This procedure is repeated two more times with a stool sample being smeared in windows marker “B” and “C”. You can store the sample on the Hemoccult slide for up to 7 days. Be sure to keep the sample in a safe place away from heat, light, and children. Your healthcare provider will give you directions of where to take or mail your stool samples. 

    Lab Results

    The lab will send the results of your test directly to your physician who will contact you to discuss the results. If your doctor suspects that you may have received a false positive or false negative test you will probably be asked to repeat the test. 

    Negative result. If there is no blood test detected in your stool sample your fecal occult blood test is negative. Your doctor may recommend that you repeat the test every year if you are at risk for colon cancer. 

    Positive result. Blood detected in the stool sample will cause the fecal occult blood test to return to you with a positive result. In this case, your physician will most likely advise you to schedule a colonoscopy to find the source of bleeding. 

    Cologuard™ (Multitarget Stool DNA Test)

    The Cologuard home colon cancer screening test detects cancer by identifying DNA markers and occult blood in stool samples. You are not required to change your diet or medications before this test. Once you collect a sample of your stool, you will send or drop off your sample to a lab. The lab will return the results to your physician or healthcare provider who will contact you as soon as they arrive. 

    Each Cologuard kit contains the following:

    • Patient guide instructions and how to return your kit pamphlet
    • 1 bottle of liquid preservative
    • 1 sample container
    • 1 tube (contains liquid solution)
    • 1 bracket
    • 1 Shipping box


    1. Check the expiration date on the outside of the shipping box. If it is expired, ask your doctor for a new one. 
    2. Choose a time to collect your sample that allows you to return the sample promptly. 
    3. Unfold the sides of the bracket after you remove the bracket from the box. 
    4. Raise the lid and seat of the toilet. 
    5. If you have to urinate, do so before the test.
    6. Place the bracket toward the back of the toilet under the toilet seat. 
    7. Unscrew container lid, set aside, and place container into  the top of the bracket.

    During procedure

    1. Sit on the toilet and have bowel movement as usual. 
    2. Collect a sample no larger than the bottle of liquid included in the box.
    3. Lift the sample container with stool from the bracket and set it on a flat surface. 
    4. Remove the bracket and throw it away or recycle it. 
    5. If you need to finish using the bathroom, do so. 
    6. Scrape stool sample with provided grooved probe.
    7. Do not fill the tube with stool.
    8. Place the probe back into the open end of the tube and close the cap.
    9. Remove the preservative from the box and unscrew the cap. 
    10. Pour the entire contents of the liquid preservative into the container with stool sample. 
    11. Place the lid on top of the container and close tightly with the lid straight.


    1. Label your samples using the sample label card as an example. 
    2. Print the information with a pen. 
    3. Wrap one sample label around the tube. 
    4. Place one sample label on the lid of the stool sample container. 
    5. Place samples inside the zippered bag inside the tray that is inside the shipping box. 
    6. Be sure to push extra air out of the bag before zipping the bag close. 
    7. Fold the zipped bag into the box and close the flaps of the box. 
    8. Refer to the return instructions to return your samples. 

    You can store your kit before you are ready to use it in a cool, dry place. Keep the kit out of the reach of children and away from direct sunlight and heat. Your sample needs to be tested soon after you collect it so choose a day that is not a holiday or weekend to take the test. 

    Lab results

    Once the lab sends the results back to your physician you will be contacted to discuss the results. Generally, there are three results given:

    Positive result. This indicated that the test detected blood in the stool or abnormal DNA in the colon lining cells shed in the sample. A positive finding could mean that there are precancerous or cancerous cells found in the sample. Some positive cases are the result of a false positive, which means there is no cancer or precancer present. All positive results are typically followed up by a colonoscopy. 

    Negative result. A negative result indicates that there was no abnormal DNA or stool detected in the stool sample. One should be aware, however, that this can be caused by a false negative result, which means cancer or precancerous cells are present but were not detected. Talk to your healthcare provider if you want further testing or have any questions about the results. 

    No result obtained. In this case, the lab was unable to produce a result from the sample that was provided. You may need to repeat the test. Ask your physician to see what the next steps hold. 


    Cancer Care Ontario Writing Staff.  (2021). Fecal Immunochemical Test (FIT) Instructions. Retrieved from Cancer Care Ontario:

    Cancer Care Ontario Writing Staff.  (2021). FIT Instructions Pamphlet. Retrieved from Cancer Care Ontario:

    Exact Sciences Writing Staff. (2020, July 07). Cologuard™ patient guide. Retrieved from Cologuard:

    Kaur, K., & Adamski, J. J. (2020, August 16). Fecal Occult Blood Test. Retrieved from StatPearls:

    Memorial Sloan Kettering Cancer Center. (2020, August 04). How to do a fecal occult blood test (FOBT). Retrieved from MSKCC:

    U.S. National Library of Medicine. (2020, July 31). Fecal occult blood test (FOBT). Retrieved from MedlinePlus: