To detect inflammation in the intestines; to distinguish between inflammatory bowel disease (IBD) and non-inflammatory bowel conditions; to monitor IBD activity
Calprotectin
Calprotectin
Also Known As
Fecal Calprotectin
Stool Calprotectin
This article was last reviewed
on
This article waslast modified
on March 24, 2021.
At a Glance
Why Get Tested?
When To Get Tested?
When you have bloody or watery diarrhea, abdominal cramps, with or without fever, lasting more than a few days
Sample Required?
A stool sample is collected in a clean container provided by the laboratory. This sample should be uncontaminated by urine or water.
Test Preparation Needed?
None
Accordion Title
Common Questions
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How is it used?
Calprotectin is a stool (fecal) test that is used to detect inflammation in the intestines. Intestinal inflammation is associated with, for example, some bacterial infections and, in people with inflammatory bowel disease (IBD), it is associated with disease activity and severity. The calprotectin test is not diagnostic but may be used to distinguish between IBD and non-inflammatory disorders and to monitor the severity of IBD.
A healthcare practitioner may order a calprotectin test to help investigate the cause of a person's persistent watery or bloody diarrhea. The test may be ordered along with other stool tests, such as a stool culture to detect a bacterial infection, a test for ova and parasites (O&P), a stool white blood cell test, and/or a fecal occult blood test (FOBT). If a healthcare practitioner suspects inflammation, then a blood test that detects inflammation in the body, such as a C-reactive protein (CRP), or an erythrocyte sedimentation rate (ESR) if CRP is not available, may also be ordered. Testing is performed both to help determine what is causing a person's symptoms and to rule out conditions with similar symptoms. This means that additional blood and stool testing may be performed depending on the suspected causes.
A calprotectin test may be ordered to help determine whether an endoscopy is indicated if IBD is suspected. A diagnosis of IBD is usually confirmed by performing an endoscopy (colonoscopy or sigmoidoscopy) to examine the intestines and by obtaining a small tissue sample (biopsy) to evaluate for inflammation and changes in tissue structures. This testing is invasive and is less likely to be necessary if inflammation is not present.
A calprotectin test may be ordered if a person with IBD has symptoms that suggest a flare-up, both to detect disease activity and to help evaluate its severity. For example, if a person has a moderately elevated calprotectin, then testing may be repeated several weeks later to see if it has stayed moderately elevated, increased, or returned to normal.
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When is it ordered?
A calprotectin test may be ordered when a person has symptoms that suggest inflammation of the digestive system and when a healthcare practitioner wants to distinguish between IBD and a non-inflammatory bowel condition.
Signs and symptoms of IBD will vary from person to person and over time. They may include one or more of the following:
- Bloody or watery diarrhea
- Abdominal cramps or pain
- Fever
- Weight loss
- Rectal bleeding
- Weakness
Testing for calprotectin may be performed when a healthcare practitioner wants to determine whether an endoscopy (colonoscopy or sigmoidoscopy) is likely or less likely to be necessary.
When a person has been diagnosed with IBD, a calprotectin test may be ordered whenever a flare-up is suspected, both to confirm disease activity and to evaluate its severity.
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What does the test result mean?
An elevated calprotectin level is a person's stool indicates that inflammation is likely present in the intestines but does not indicate either its location or cause. In general, the degree of elevation is associated with the severity of the inflammation.
Increases in calprotectin are seen with IBD, but also with bacterial infections, some parasitic infections, and with colorectal cancer. An endoscopy (colonoscopy or sigmoidoscopy) may be indicated as a follow-up test to help determine the cause of inflammation, signs, and symptoms.
In people newly diagnosed with IBD, concentrations of calprotectin may be very high.
A low calprotectin means that signs and symptoms are likely due to a non-inflammatory bowel disorder. Examples of these include viral infections in the digestive tract and irritable bowel syndrome (IBS). Unlike IBD, IBS does not cause inflammation. Rather, it causes cramp-like stomach pains and spasms with bouts of diarrhea and/or constipation. In people with low calprotectin results, an endoscopy is less likely to be indicated or useful.
A moderate calprotectin level may indicate that there is some inflammation present or that a person's condition is worsening. A repeated calprotectin test with a result that is still moderately elevated or that has increased is likely to require further investigation and may warrant an endoscopy.
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Is there anything else I should know?
Anything that causes inflammation in the intestines can cause an increase in stool calprotectin.
Calprotectin can be increased with the intestinal tissue damage and bleeding that is sometimes seen with use of non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen.
Calprotectin is related to another stool test, lactoferrin. Both are substances that are released by white blood cells in the stool and are associated with intestinal inflammation.
In some cases, calprotectin may be low even when inflammation is present (a false negative). This is most frequently seen with children.
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Can a blood test be substituted for a stool calprotectin test?
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What can I do to decrease my calprotectin?
Calprotectin is a reflection of gastrointestinal inflammation and is not affected by lifestyle changes. If it is due to an infection, then it will most likely return to normal when the infection resolves. If it is due to inflammatory bowel disease, then it will rise and fall with disease activity. In the rare case that an elevated calprotectin is caused by non-steroidal anti-inflammatory drug (NSAID) therapy, then it is likely to return to normal when the medication is discontinued.
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How long will it take for my calprotectin results?