A laboratory analysis of a stool sample is a non-invasive procedure used by healthcare providers to assess the function and health of the gastrointestinal tract. This testing helps diagnose conditions ranging from bacterial or parasitic infections to inflammatory bowel disease or colorectal cancer. Since the accuracy of the results depends on the specimen’s integrity, carefully following the collection protocol provided in the test kit is essential. Requirements for preparation, collection, and storage differ based on the specific test ordered, so reviewing all instructions is the first step.
Preparing for Collection
Prior to the bowel movement, consider any pre-collection requirements, which vary significantly depending on the specific test ordered. Certain analyses, such as the Fecal Occult Blood Test (FOBT), may require temporary dietary changes to prevent false results. For instance, you might be instructed to avoid red meat, high doses of Vitamin C, and certain raw vegetables for several days before collection. These restrictions ensure the test detects only human blood, not interference from plant or animal enzymes.
Similarly, some medications can interfere with the detection of pathogens or other markers. A physician may advise pausing non-steroidal anti-inflammatory drugs (NSAIDs), antacids, or Pepto-Bismol. Before the bowel movement, arrange the physical setup for collection. This involves placing a specialized collection device, often called a “hat” or collection sheet, securely over the toilet bowl rim to catch the specimen.
Step-by-Step Sample Retrieval
The initial step is to pass the stool directly into the prepared collection device, avoiding contamination from urine or toilet water. Water contamination can dilute the sample, and urine can inhibit bacterial growth in a culture test or alter the specimen’s chemical balance. Open the container provided by the lab, which often includes a small spoon, scoop, or swab attached to the lid.
Use the provided tool to transfer a small amount of the stool specimen into the collection container. If the stool is formed, collect samples from several different areas, such as the ends and the middle, to ensure a representative sample. If the stool is loose, liquid, or contains visible blood or mucus, prioritize collecting from those specific areas. If the container includes a preservative liquid, add the sample until the contents reach the specific “fill-to” line. Once the sample is secured, screw the lid on tightly to prevent leakage, and flush the remaining stool.
Storage and Transport Guidelines
Immediately after sealing the container, label the specimen correctly with the required patient information. This typically includes the full name, date of birth, and the exact date and time of collection. The required storage temperature differs significantly based on the type of test ordered, making consultation of the specific kit instructions mandatory. Some tests, such as those for Clostridium difficile, require refrigeration to maintain stability, while others with chemical preservatives may need to be kept at room temperature.
Place the sample into the biohazard bag supplied in the kit, securing it for safe handling and transport. Time sensitivity is a major factor for most stool analyses, and the specimen must be delivered to the lab or clinic as quickly as possible. Many laboratories require the sample to be received within 24 to 48 hours of collection. Delays can degrade the specimen, causing the test results to be inaccurate or rejected.