From the Guidelines
The H. pylori stool test is a reliable and preferred non-invasive method for detecting Helicobacter pylori infection, especially when used in conjunction with other diagnostic strategies and considering patient preferences and local test availability 1. When performing the H. pylori stool test, it is essential to follow the recommended guidelines to ensure accurate results.
- The test requires a small stool sample, which should be collected using the provided kit and returned to the laboratory promptly, usually within 24 hours.
- Patients should avoid taking antibiotics for at least 4 weeks and proton pump inhibitors (PPIs) for 2 weeks before the test to prevent false negative results, as these medications can temporarily reduce the bacterial load in the stomach 1.
- The test detects H. pylori antigens in the stool sample, and results are typically available within a few days.
- If the test is positive, treatment usually involves a regimen of two antibiotics, such as amoxicillin and clarithromycin, plus a PPI, like omeprazole, for 7-14 days, which effectively eradicates the bacteria in most cases 1. It is crucial to note that the diagnostic strategy should reflect not only the clinical indication but also the local availability and costs of the different tests, as well as patient preferences 1.
- Non-invasive tests, such as the urea breath test (UBT) and the stool antigen test, are preferred over invasive methods, like endoscopy, due to their ease of use and lower risk of complications 1.
- Serologic tests, which detect anti-H. pylori IgG antibodies, are generally not recommended due to their low specificity and sensitivity, and the fact that they remain positive long after the infection has been eradicated 1.
From the Research
H pylori Stool Test
- The H pylori stool test, also known as the stool antigen test (SAT), is a non-invasive diagnostic method used to detect H pylori infection 2.
- The test detects the presence of H pylori antigens in the stool, which are produced by the bacteria 2.
- There are two types of SATs: enzyme immunoassay (EIA) and immunochromatography (ICA) 2.
- SATs are useful for primary diagnosis and for assessing eradication therapy 2.
- The accuracy of SATs can be affected by factors such as the quality of the stool sample, temperature, and the interval between sample collection and measurement 2.
Comparison with Other Diagnostic Methods
- The diagnostic accuracy of SATs has been compared to other non-invasive tests, such as the urea breath test and serology 3.
- A study found that the urea breath test had higher diagnostic accuracy than SATs and serology 3.
- However, SATs are still considered a useful diagnostic tool, especially in certain populations such as children and post-gastric surgery patients 2, 4.
Clinical Applications
- The H pylori stool test can be used to diagnose H pylori infection in symptomatic patients, including those with epigastric pain, heartburn, and nausea or vomiting 4.
- The test can also be used to monitor the effectiveness of eradication therapy 2.
- In addition, SATs can be used in epidemiological studies to detect H pylori infection in asymptomatic individuals 5.