A stool sample is fecal matter collected for lab analysis. These samples provide valuable insights, helping healthcare providers diagnose conditions like infections, inflammation, and other gastrointestinal issues. Accurate test results depend on proper collection and handling. Following specific guidelines for obtaining, storing, and transporting your sample ensures its integrity.
Getting Your Sample
Collecting a stool sample requires careful preparation to prevent contamination. Always read and follow the specific instructions provided by your healthcare provider or included with your collection kit. Before starting, ensure you have all necessary supplies, such as the collection hat or device, sterile specimen cups, and a wooden stick or scoop. Wash your hands thoroughly with soap and water both before and after collection.
To avoid urine contamination, urinate into the toilet before stool collection. Do not collect the sample directly from toilet bowl water, as this can introduce contaminants like water, urine, or disinfectant, which can interfere with test accuracy. Instead, use a collection device, such as a “hat” placed under the toilet seat, plastic wrap spread over the toilet rim, or a clean bedpan.
Collect a sufficient amount of stool, typically about one tablespoon or two to three scoopfuls, ensuring to include any areas that appear watery, bloody, or slimy if present. If your kit includes multiple cups, distribute portions from the same bowel movement into each. Immediately transfer the sample into the sterile container, seal it tightly, and label it with your full name, date of birth, and the date and time of collection.
Storing Your Sample Correctly
Correct storage of your stool sample is essential for accurate lab results. The appropriate storage method and duration vary depending on the specific tests ordered, as different analytes and microorganisms have varying stability. Always seal the container tightly after collection to prevent leakage and exposure.
For many common tests, refrigeration at temperatures between 2-8°C (36-46°F) is recommended. This temperature range helps slow bacterial growth and prevents the degradation of unstable compounds. For instance, C. difficile toxins and calprotectin can degrade at room temperature, making refrigeration important for their stability. While some tests allow refrigeration for up to 24-48 hours, others, like calprotectin, may remain stable for up to 3 to 7 days when refrigerated.
Certain tests may require the sample to remain at room temperature (20-25°C / 68-77°F) for very short periods, such as 2 to 4 hours. Prolonged storage at room temperature is discouraged because it can lead to bacterial overgrowth and the breakdown of sensitive biological markers. For long-term storage, especially if there will be a delay in transport, freezing the sample at -20°C or even -70°C is often recommended, particularly for antigen or PCR-based tests. Frozen samples can remain stable for weeks to several months, though specific components, such as C. difficile toxins, may show varied stability at different freezing temperatures.
Sending Your Sample to the Lab
Once your stool sample is collected and properly stored, preparing it for transport to the laboratory is the final step. Begin by placing the sealed specimen container inside a plastic biohazard bag, which is often provided in your collection kit. This bag should be leakproof and contain absorbent material capable of containing the entire sample in case of an accidental leak. The primary container itself should be watertight and able to withstand typical pressure changes during transit.
For additional protection and compliance with transport regulations, the biohazard bag containing the sample should be placed within a secondary, rigid outer container or box. If the sample needs to be kept cold, include ice packs for refrigerated samples or dry ice for frozen samples within this outer packaging. Ensure all required documentation, such as the laboratory requisition form with patient information and the date and time of collection, is securely included with the sample but kept separate from the biohazard bag. Finally, deliver the sample to the designated lab or drop-off point as soon as possible, ideally within the time frame specified by your healthcare provider, to ensure timely processing and accurate test results.