What is a white blood cell (WBC) in stool test? 

This test looks for white blood cells, also known as leukocytes, in your stool. White blood cells are part of the immune system. They help your body fight off infections and other diseases. If you have leukocytes in your stool, it can be a sign of a bacterial infection that affects the digestive system. These include: 

• Clostridium difficile (C. diff), an infection that most often happens after someone takes antibiotics. Some people with C. diff could develop life-threatening inflammation of the large intestine. It mostly affects older adults. 
• Shigellosis, an infection of the lining of the intestine. It is spread by direct contact with the bacteria in the stool. This can happen if an infected person doesn’t wash their hands after using the bathroom. The bacteria can then be passed in food or water that this person handles. It mostly affects children under the age of 5. 
• Salmonella, a bacterium mostly found in undercooked meat, poultry, dairy, and seafood, and inside eggs. You can get the disease if you eat contaminated food. 
• Campylobacter, a bacteria found in raw or undercooked chicken. It can also be found in unpasteurized milk and contaminated water. You can get the disease by eating or drinking contaminated food. 

Leukocytes in stool can also be a sign of inflammatory bowel disease (IBD). IBD is a type of chronic disorder that causes inflammation in the digestive system. Common types of IBD include ulcerative colitis and Crohn’s disease. 

Both IBD and bacterial infections of the digestive system can cause severe diarrhea, abdominal pain, and dehydration, a condition in which your body doesn’t have enough water or other fluids to function normally. In some cases, these symptoms can be life-threatening. 

Other names: leukocytes in stool, stool WBC, fecal leukocyte test, FLT 

What is it used for? 

A white blood cell in stool test is most often used to find out the cause of severe diarrhea that’s lasted for more than four days. 

Why do I need a white blood cell in stool test? 

Your health care provider may order a white blood cell in stool test if you or your child has any of the following symptoms: 

• Watery diarrhea three or more times a day, lasting for more than four days 
• Abdominal pain 
• Blood and/or mucus in the stool 
• Fever 
• Fatigue 
• Weight loss 

What happens during a white blood cell in stool test? 

You will need to provide a sample of your stool. Your provider or your child’s provider will give you specific instructions on how to collect and send in your sample. Your instructions may include the following: 

• Put on a pair of rubber or latex gloves. 
• Collect and store the stool in a special container given to you by your health care provider or a lab. You may get a device or applicator to help you collect the sample. 
• Make sure no urine, toilet water, or toilet paper mixes in with the sample. 
• Seal and label the container. 
• Remove the gloves and wash your hands. 
• Return the container to your health care provider or the lab by mail or in person. 

Will I need to do anything to prepare for the test? 

Certain medicines and foods may affect the results. Ask your provider or your child’s provider if there are any specific things you need to avoid before the test. 

Are there any risks to the test? 

There is no known risk to having a white blood cell in stool test. 

What do the results mean? 

A negative result means no white blood cells (leukocytes) were found in the sample. If you or your child’s results were negative, the symptoms are probably not caused by an infection. 

A positive result means white blood cells (leukocytes) were found in your stool sample. If you or your child’s results show leukocytes in stool, it means there is some kind of inflammation in the digestive tract. The more leukocytes that are found, the higher the chance that you or your child has a bacterial infection. 

If your provider thinks you have an infection, he or she may order a stool culture. A stool culture can help find out which specific bacteria is causing your illness. If you are diagnosed with a bacterial infection, your provider will prescribe antibiotics to treat your condition. 

If your provider suspects C. diff, you may first be told to stop taking the antibiotics you are currently using. Your provider may then prescribe a different type of antibiotics, which target C diff bacteria. Your provider may also recommend a type of supplement called probiotics to help your condition. Probiotics are considered “good bacteria.” They are helpful to your digestive system. 

If your provider thinks you have inflammatory bowel disease (IBD), he or she may order further tests to confirm a diagnosis. If you are diagnosed with IBD, your provider may recommend dietary and lifestyle changes and/or medicines to help relieve your symptoms. 

Is there anything else I need to know about a white blood cell in stool test? 

If your symptoms or your child’s symptoms are not too severe, your provider may treat the symptoms without making a more definite diagnosis. Treatment usually includes drinking plenty of water and restricting the diet to bland foods for several days. 

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Source: MedlinePlus, National Library of Medicine