What is a Fecal Occult Blood Test?

A Fecal Occult Blood Test (FOBT) is a medical diagnostic tool to detect hidden, or 'occult,' blood in one's stool. This test is vital in identifying early signs of several health complications, notably colorectal cancer. The presence of unseen blood in the stool can indicate a problem in your digestive system, such as a growth, or 'polyp,' or other conditions like ulcers, hemorrhoids, or more severe issues like cancer.

The FOBT is a non-invasive procedure that can be carried out in the comfort of your home, requiring only a tiny sample of your stool. The process involves using a specialized test kit, which usually requires samples from two or three bowel movements for accurate results. The collected samples are then sent to a lab for analysis.

This test explicitly uses a chemical called guaiac to detect the presence of hemoglobin in the stool. Hemoglobin is a protein found in red blood cells, and its presence in the feces might indicate bleeding in the digestive tract. However, it's important to note that the FOBT is a screening tool, not a diagnostic test. A positive result indicates the need for further investigation, not a confirmed diagnosis.

You can also glean more insights on Fecal Occult Blood Tests and how they fit into broader clinical documentation processes. This knowledge will empower you to manage your health and wellness proactively.

How does it work?

The Fecal Occult Blood Test (FOBT) operates on a straightforward yet efficient mechanism. Its primary function is to identify the presence of minuscule amounts of blood in the feces, which are often invisible to the naked eye. This test is instrumental in detecting early signs of various health conditions, particularly colorectal cancer. It's worth noting that the FOBT is a non-invasive, at-home screening tool, making it a convenient choice for preliminary testing.

  1. Acquire a FOBT Kit: Obtain a printable Fecal Occult Blood Test kit online at Carepatron. Ensure you read the instructions carefully before starting the process.
  2. Sample Collection: Using the tools provided in the kit, collect a small sample of your stool. This process may need repeated over two or three bowel movements to ensure accurate results.
  3. Application of Sample: Apply the collected stool sample to the designated areas on the test card or slide included in the kit.
  4. Waiting Period: After applying the sample, you must wait for the designated time mentioned in the instructions. This waiting period allows the sample to react with the chemicals in the test kit.
  5. Reading the Results: Once the waiting period is over, use the developer solution in the kit to reveal the results. If the test area changes color, it indicates the presence of blood in the stool sample.

The FOBT is a crucial health screening tool that can save lives by detecting early signs of serious health conditions. However, it's important to remember that while the FOBT can indicate potential issues, it is not a definitive diagnostic tool. Positive results should always be followed up with further medical consultation and testing.

When would you use this test?

The Fecal Occult Blood Test (FOBT) is a critical tool in preventive healthcare, particularly for digestive tract conditions. It is typically recommended for individuals over 50 for routine colon cancer screening. This is because the risk of developing colon cancer increases significantly after this age.

Additionally, individuals with a family history of colon cancer may be advised to take this test at a younger age. This proactive approach can help detect abnormalities early, increasing the chances of successful treatment.

The FOBT may also be suggested for those experiencing unexplained weight loss or rectal bleeding symptoms. These symptoms could signal various health issues, including digestive tract disorders or colorectal cancer. The test helps identify hidden blood in the stool, an early sign of these conditions.

To understand the practical application of the FOBT, consider this scenario: An individual obtains an FOBT kit through a healthcare provider or a certified online source. The kit includes detailed instructions and all the necessary tools for the test.

Per the instructions, the individual collects small samples from two or three different bowel movements and applies them to the designated areas on the test card or slide. After waiting for the specified period, they use the developer solution to reveal the results. If the test area changes color, it indicates the presence of blood in the stool, necessitating further medical consultation and testing.

For a more detailed understanding, refer to our Fecal Occult Blood Test PDF. This resource provides comprehensive information, including step-by-step instructions for conducting the test at home.

What do the results mean?

When you undergo a Fecal Occult Blood Test (FOBT), the results serve as an initial indicator of potential health issues within your digestive system. It's important to note that the FOBT is a screening tool, not a diagnostic one. Therefore, while the outcome can guide subsequent medical steps, it does not provide a definitive diagnosis.

A positive FOBT result indicates that blood has been detected in your stool sample. This finding can be associated with various conditions, from relatively benign issues like hemorrhoids or ulcers to more serious concerns such as polyps or colorectal cancer. Polyps are small growths on the colon's lining, some of which may develop into cancer over time. Blood could also indicate diverticulosis or inflammation in the digestive tract.

However, a critical aspect to remember is that a positive result does not automatically imply that you have colon cancer or any other specific disease. The test merely identifies the presence of blood, not its source or the cause. Further investigations, such as a colonoscopy or sigmoidoscopy, are required for a concrete diagnosis.

On the other hand, a negative FOBT result means no blood was found in the stool sample. Generally, this is a reassuring result, suggesting no immediate concerns related to conditions causing bleeding in the digestive tract. However, it doesn't completely exclude the possibility of disease. Some conditions, like certain polyps or cancers, might not always cause detectable bleeding. Therefore, regular screenings are still recommended, particularly for individuals at a higher risk due to factors such as age or family history.

The FOBT is a valuable first step in detecting various digestive tract disorders early. Our free Fecal Occult Blood Test makes it an accessible option for many individuals. However, following up on any positive result with further testing and consultation with a healthcare professional to determine the best course of action is essential.

Research & Evidence

The Fecal Occult Blood Test (FOBT) has a long history of use in medical practice, dating back to the early 1900s. It was created to detect subtle blood loss in the gastrointestinal tract, a potential indicator of polyps, colorectal cancer, or other digestive disorders.

Over the years, research has consistently shown the FOBT to be a valuable tool in the early detection of colon cancer. Regular screening using this test can identify cancer at an initial stage, when it is most treatable, leading to better patient outcomes and reduced mortality rates.

However, the traditional guaiac-based FOBTs (gFOBTs) had significant limitations, including more specificity for human blood and susceptibility to dietary influences. To overcome these issues, fecal immunochemical tests (FITs) for hemoglobin were developed. Since their invention by Suovaniemi et al. in the 1980s, FITs have grown in popularity due to their increased sensitivity and specificity.

A study published in 'Anticancer Research' noted an increasing number of FITs being developed, particularly in the last two decades, further advancing the field of colorectal cancer screening. FITs are more effective than gFOBTs, detecting cancers and advanced adenomas more accurately.

Notwithstanding the advances in testing methods, the primary role of FOBTs remains to detect hidden blood in the stool as an early warning sign of potential health issues. The evolution of these tests over time, backed by extensive research and evidence, underscores their critical importance in preventive healthcare, especially regarding colorectal cancer.


  1. Robertson, D. J., & Lee, J. K. (2015). Advances in Fecal Occult Blood Tests: The FIT Revolution. Digestive Diseases and Sciences, 60(3), 609–622. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4366567/
  2. Oort, F. A., Terhaar sive Droste, J. S., Coupe, V. M., van der Hulst, R. W., Wesdorp, E. C., Scholten, E. T., ... & van Turenhout, S. T. (2019). Use and abuse of fecal occult blood tests: a community-based study on patients in a managed care program. BMC Gastroenterology, 19(1), 145. Retrieved from https://bmcgastroenterol.biomedcentral.com/articles/10.1186/s12876-019-1079-9
  3. Katsoula, A., Paschos, P., Haidich, A. B., Tsapas, A., & Giouleme, O. (2020). Diagnostic accuracy of fecal immunochemical test in patients at increased risk for colorectal cancer: A meta-analysis. Journal of the American College of Cardiology, 76(6), 664–676. Retrieved from https://ar.iiarjournals.org/content/40/2/575
Who typically requests a Fecal Occult Blood Test?
Who typically requests a Fecal Occult Blood Test?

Commonly asked questions

Who typically requests a Fecal Occult Blood Test?

Doctors typically recommend a Fecal Occult Blood Test for individuals with a family history of colon cancer, over 50, or with symptoms such as rectal bleeding or unexplained weight loss.

When are Fecal Occult Blood Tests used? 

Fecal Occult Blood Tests are used in routine colon cancer screening for individuals without symptoms and for screening individuals with symptoms such as rectal bleeding or unexplained weight loss.

How are Fecal Occult Blood Tests used? 

Fecal Occult Blood Tests detect microscopic amounts of blood in the stool that may not be visible to the naked eye. It involves collecting a small sample of stool using a test kit.

How long does a Fecal Occult Blood Test take? 

A Fecal Occult Blood Test takes around 10-15 minutes to complete.

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