Calprotectin Stool Test
Reviewed
Also called: Fecal calprotectin test, Fecal calprotectin
A calprotectin stool test measures a protein called calprotectin in a sample of your stool (poop).
Specimen: Stool
Why this test may be ordered
- To check for inflammation in the intestines when you have long‑lasting or recurring diarrhea, belly pain, and cramping.
- To help distinguish between IBD (which involves inflammation) and IBS (which does not).
- To monitor how severe inflammation is in people already diagnosed with IBD, guide treatment choices, check if IBD is improving or worsening, and predict the chance of symptom return.
Preparation and collection
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. Proton pump inhibitors (PPIs), which are used to control stomach acid and relieve symptoms of GERD.
You will need to provide a stool sample for your test. There are different ways to collect stool samples, so follow the instructions carefully. Make sure the stool doesn't mix with any urine (pee), toilet paper, or water from the toilet.
There is no known risk to having a calprotectin stool test.
Understanding results
It's normal to have a small amount of calprotectin in your stool. But high levels are a sign that your intestines are inflamed.
- Normal or low levels of calprotectin: Normal or low levels of calprotectin usually mean that your intestines are not inflamed, which means you don't have inflammatory bowel disease (IBD). Your symptoms are probably caused by a type of non-inflammatory condition. Limitation: But it's possible to have normal calprotectin test results even when your intestines are inflamed. This is called a "false negative." False negative calprotectin results mostly happen in children. Next step: Your provider may order other tests to figure out which condition is causing your symptoms.
- High levels of calprotectin: High levels of calprotectin usually mean that your intestines are inflamed. Very high levels of calprotectin are often linked to: Inflammatory bowel disease (IBD), Food poisoning caused by certain types of bacteria. Limitation: Several conditions can cause high calprotectin levels, so you may need other tests to find the cause. Next step: If your calprotectin levels are high, your provider may retest you in a few weeks to see if they change.
- Cannot diagnose the specific cause of inflammation; only indicates presence or absence of intestinal inflammation.
- False negatives can occur, especially in children.
- Certain medications (NSAIDs, proton pump inhibitors) can affect results.
What to do next
If your calprotectin test results show that your intestines are inflamed, your provider may order a colonoscopy, which uses a tiny camera to look inside your intestines.
- Do you have severe watery or bloody diarrhea with abdominal pain or cramping lasting more than a few days?
- Do you have blood, mucus, or pus in your stool?
- Do you have a feeling of urgency to move your bowels or a feeling of needing to move your bowels even when there is no stool?
- Have you had unexplained weight loss?
- Have you been diagnosed with inflammatory bowel disease (IBD) and need to monitor your condition?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.