wie lange darf man eine stuhlprobe aufbewahren — what are common causes?

The storage duration of a stool sample depends on the intended analysis. For microbiological culture, the sample should ideally reach the lab within 2–4 hours; if refrigerated at 4 °C, storage up to 24 hours is acceptable. For parasitology (e.g., ova and parasites), fresh material (<1 hour) or preservation in specific fixatives is required. For molecular tests (PCR) targeting bacterial or viral DNA/RNA, the sample can be stored at 4 °C for up to 48 hours or frozen at -20 °C for longer periods. For calprotectin measurement (intestinal inflammation), refrigeration for 1–2 days is possible. Common causes of invalid samples include: prolonged storage at room temperature (bacterial overgrowth, DNA degradation), incorrect container (e.g., urine cup instead of stool tube), contamination with urine or water, and insufficient quantity. Always follow the specific instructions provided with the test kit. The provided context does not contain information on stool sample storage; this answer is based on general medical practice.