wann ist eine stuhlprobe unbrauchbar — when to see a doctor?

A stool sample is unusable if it was not stored correctly (e.g., >24 h at room temperature), contaminated with urine or water, or if the container is leaking or mislabeled. Diarrheal samples or those collected after contrast agents (e.g., barium) may also be invalid. You should see a doctor if you experience persistent diarrhea, blood in stool, unexplained weight loss, severe abdominal pain, or fever – regardless of the sample. The lab determines sample adequacy; always follow the specific collection instructions from your test provider. Note: The provided context does not contain specific stool sample criteria; this answer is based on general medical practice.