White Blood Cell (WBC) in Stool
Reviewed
Also called: Leukocytes in stool, Fecal leukocyte test, Stool WBC, Fecal WBC
This test looks for white blood cells in a sample of your stool (poop). White blood cells are also called leukocytes.
Specimen: stool
Urgent safety information
See your provider right away if you have: Signs of dehydration, including dry mouth, dark urine (pee), fatigue, or dizziness, A fever of 102 degrees or higher, Unintentional weight loss, Severe pain in the abdomen (belly) or rectum, Stool that is black and tarry or contains blood or pus, In adults: frequent vomiting, diarrhea 6 or more times in 24 hours, or diarrhea for more than 2 days, In young children and infants: diarrhea for more than 24 hours.
Why this test may be ordered
- To find out whether diarrhea is caused by inflammation in the digestive system
- Possible bacterial infection, such as C. diff
- Possible inflammatory bowel disease or amebiasis
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.
You will need to provide a stool sample for your test. Your provider will probably give you a container or kit with instructions on how to collect the sample. Make sure the stool doesn't mix with any urine, toilet paper, or water from the toilet. If you are unable to return the container right away, you should refrigerate your sample until you're ready to deliver it.
There is no known risk to having a white blood cell in stool test.
Understanding results
A white blood cell in stool test can't diagnose the exact condition that's causing diarrhea. But it can help narrow down the possible causes to conditions that either do or don't involve inflammation.
- Positive or abnormal: A positive or abnormal test result means that white blood cells were found in your stool sample. That means you have inflammation in your digestive tract. Limitation: A white blood cell in stool test can't diagnose the exact condition that's causing diarrhea. Next step: This information helps rule out conditions that don't cause inflammation, including viral infections, certain bacteria, and most parasites. But to determine which condition or bacterial infection is causing your inflammation, your provider will order additional tests.
- Negative or normal: A negative or normal test result means that no white blood cells were found in your stool sample. That may mean that inflammation isn't causing your illness. Limitation: But a normal test result can't rule out conditions that cause inflammation. That's because white blood cells don't last long in a stool sample. Next step: Your provider may use a calprotectin stool test if a WBC in stool test doesn't give them a clear understanding of what's causing your diarrhea.
- It can't diagnose the exact cause of diarrhea.
- White blood cells break down quickly, so a normal result can't rule out inflammation.
- Certain medicines and foods may affect results.
What to do next
Your provider may use a calprotectin stool test if a WBC in stool test doesn't give them a clear understanding of what's causing your diarrhea.
- Do I need to avoid any medicines or foods before this test?
- What other tests might I need if white blood cells are found?
- Would a calprotectin test help in my case?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.
U.S. National Library of Medicine: White Blood Cell (WBC) in Stool