How long can a routine stool sample be stored?

After collecting a routine stool specimen, it should be kept at room temperature for no more than 1 hour. If refrigerated (2–8°C), the specimen can be stored for up to 24 hours. Exceeding these time limits may lead to specimen degradation and microbial growth, which could compromise the accuracy of test results. If the specimen has been stored beyond the recommended time or if abnormal results occur, it is advisable to seek medical attention promptly to clarify the situation.

In room temperature conditions, moisture in the stool easily evaporates, and microorganisms such as bacteria and parasite eggs may rapidly multiply or decompose. This can alter cell morphology and disrupt microbial balance, leading to inaccurate measurements of white and red blood cells and misjudgment of pathogens, thus failing to reflect the true condition of the intestines.

Although refrigeration slows down microbial proliferation, prolonged storage still affects specimen quality. For example, reduced viability of parasite eggs may result in missed detection, and changes in chemical components may affect test results such as fecal occult blood testing. Therefore, even when refrigerated, specimens must be delivered to the laboratory within 24 hours.

When collecting a stool specimen, use a clean, dedicated container and collect a fresh sample about the size of a soybean. Avoid contamination with urine, wastewater, or other impurities. When refrigerating, ensure the container is sealed to prevent cross-contamination, and remove the specimen from refrigeration 30 minutes before testing to allow it to return to room temperature.