Stool Examination

A stool examination is a laboratory test that analyzes a patient's feces to detect infections, parasites, blood, fat, mucus and chemical abnormalities. Methods include microscopy for ova and parasites, culture or molecular tests for bacteria and viruses, and fecal occult blood or antigen assays. Results help diagnose causes of diarrhea, gastrointestinal bleeding, inflammation, malabsorption and guide appropriate treatment.

Follow lab instructions and collect using the provided sterile container and spatula. Avoid contaminating the sample with urine or toilet water. Gather the required amount, label with name, date and time, and refrigerate if you can’t deliver it within a few hours. Stop antibiotics, probiotics, bismuth or laxatives if your clinician advises. Wash hands before and after collection and return the sample promptly.

A normal stool test shows soft-formed brown stool with no blood, mucus, or pus; negative occult blood; no pathogenic bacteria, viruses, or parasites on culture/microscopy; normal fecal pH and fat levels; and normal inflammatory markers (e.g., calprotectin). Microscopy finds no ova or cysts. These results indicate normal digestion, absorption, and no active infection or intestinal inflammation.

A 3-sample stool test requires collecting three separate bowel-movement specimens on different days. This improves detection of intermittent findings—parasites (ova and cysts), some bacteria, and hidden (occult) blood—by reducing false negatives. Each specimen is placed in sterile containers and returned to the lab per instructions. It’s used when symptoms are intermittent or a single sample is inconclusive.

Unless told otherwise, eat your usual diet before a stool test. For faecal occult blood tests, avoid red meat, high‑dose vitamin C, certain raw vegetables and NSAIDs/aspirin for 48–72 hours; stop iron or other supplements only if advised. For parasite testing, don’t start antibiotics or antiparasitics before sampling. Follow any specific lab or clinician instructions for collection.

Unhealthy stool signs include persistent diarrhea or constipation, very hard or watery stools, blood or dark/tarry appearance, pale or clay-colored stools, excess mucus, oily or greasy floating stools, unusually foul odor, and sudden changes in frequency or consistency. Accompanying symptoms—abdominal pain, fever, unexplained weight loss, or urgency—warrant prompt medical evaluation.