White Blood Cell (WBC) in Stool
Reviewed
Also called: leukocytes in stool, stool WBC, fecal WBC, fecal leukocyte test, FLT, FGST
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.
Specimen: stool
Why this test may be ordered
- To find out whether diarrhea is caused by inflammation in the digestive system
- For people with symptoms of inflammatory diarrhea (watery diarrhea 3+ times/day, abdominal cramps, blood/mucus in stool, fever, fatigue, weight loss)
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.
stool
There is no known risk to having a white blood cell in stool test.
Understanding results
This test looks for white blood cells in your stool, which can indicate inflammation in your digestive tract. The results are reported as either positive (white blood cells found) or negative (no white blood cells found). A positive result suggests inflammation, while a negative result does not rule it out. Your provider will use the result along with your symptoms and other tests to determine the cause of your diarrhea.
- Positive: White blood cells were found in your stool, indicating inflammation in your digestive tract. This helps narrow the cause to conditions that cause inflammation (e.g., bacterial infections, inflammatory bowel disease). Limitation: The test cannot diagnose the exact condition causing diarrhea; it only indicates whether inflammation is present. Next step: Routine
- Negative: No white blood cells were found in your stool. This may mean inflammation is not causing your diarrhea, but it cannot rule out inflammatory conditions. Limitation: A negative result does not rule out inflammation because white blood cells may break apart in the stool sample. Next step: Routine
- 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.
- What other tests might I need to identify the cause of my diarrhea?
- How should I collect the stool sample correctly?
- Can medications or foods affect my test results?
Evidence source
U.S. National Library of Medicine: White Blood Cell (WBC) in Stool