Calprotectin Stool Test

A calprotectin stool test measures a protein called calprotectin in a sample of your stool (poop). The test is also called a fecal calprotectin test. It's used to check for inflammation (swelling and irritation) in your intestines.

It's normal to have a small amount of calprotectin in your stool. But high levels are a sign that your intestines are inflamed. When you have inflammation in your intestines, your immune system sends certain types of white blood cells (neutrophils) to the inflamed area.

These white blood cells release calprotectin into your intestines where it mixes with your stool. Inflammation in your intestines can cause severe watery or bloody diarrhea with abdominal (belly) pain and/or cramping that last for more than a few days. Other types of digestive conditions can also cause these symptoms.

If these symptoms last a long time or come and go, it's important to know if your intestines are inflamed. That's because inflammation can damage the lining of your intestines and lead to other serious health conditions over time. A calprotectin test can find out whether your intestinal condition involves inflammation.

But it can't diagnose the specific cause. Knowing whether your intestines are inflamed helps your health care provider decide what other tests you may need and what treatments are best for you.

Why this test is done

Most watery diarrhea goes away on its own after a day or two, and your provider doesn't need to do tests. But if your symptoms don't improve after a few days or keep coming back, you may need a calprotectin stool test to check for inflammation in your intestines.

Along with diarrhea, belly pain and cramping, other symptoms of inflammation in your intestines may include:

• Blood, mucus, and/or pus in your stool. Contact your provider right away if you see blood or pus in your stool, or if your stool is black and tarry.
• Always feeling like you need to move your bowels (poop) even when there's no stool. This condition may be painful and cause cramps.
• Feeling an urgent need to move your bowels.
• Weight loss when you're not trying to lose weight.

If you already have IBD, you may need calprotectin testing to monitor your condition. This information helps your provider choose treatment and check whether it's working.

How to prepare

Ask your provider if you need to stop taking any medicines before your test. But never stop taking any medicine without talking with your provider first. Medicines that may affect your test results include certain over-the-counter medicines, including:

• Nonsteroidal anti-inflammatory drugs (NSAIDs), which are used to relieve pain. Examples include aspirin, ibuprofen, and naproxen.
• Proton pump inhibitors (PPIs), which are used to control stomach acid and relieve symptoms of GERD. Examples include omeprazole, esomeprazole, and lansoprazole.

Sample type

Stool

Other names for this test

Fecal calprotectin