White Blood Cell (WBC) in Stool
Reviewed
This test checks for white blood cells in a stool sample to help determine if diarrhea is caused by inflammation in the digestive tract. It is used when you have severe, prolonged diarrhea with symptoms like pain, fever, or blood in the stool. A positive result indicates inflammation, but the test cannot identify the exact cause. A negative result does not rule out inflammation. Your provider will combine this test with other evaluations to guide care.
Preparation and collection
Certain medicines and foods may affect the test results. Ask your provider if there are any specific things you need to avoid before the test.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- The test cannot diagnose the exact condition causing diarrhea; it only indicates whether inflammation is present.
- A negative result does not rule out inflammation because white blood cells may break apart in the stool sample.
- Certain medicines and foods may affect the test results.
What to do next
Your healthcare provider will interpret the results along with other tests to determine the cause of your symptoms. See your provider right away if you have signs of dehydration, diarrhea for more than 2 days, fever of 102°F or higher, severe abdominal pain, black/tarry stool, or frequent vomiting/diarrhea 6 or more times in 24 hours.
Evidence source
U.S. National Library of Medicine: White Blood Cell (WBC) in Stool