High Calprotectin: What It Means and How It Relates to IBS

What Is a Fecal Calprotectin Test?

The fecal calprotectin test is a simple, non-invasive stool test used to detect inflammation in the intestines. It measures the level of a protein called calprotectin, which is released by white blood cells (neutrophils) when there is active inflammation in the gut lining. This test is often used by doctors as a first step to help differentiate between inflammatory bowel diseases (IBD), like Crohn's disease and ulcerative colitis, and non-inflammatory functional disorders like Irritable Bowel Syndrome (IBS).

Understanding Your Calprotectin Results: Normal Range by Age

Calprotectin levels can vary, and “normal” ranges depend on the laboratory that analyzes the sample. However, general reference ranges are often categorized as follows. It is crucial to discuss your specific results with your healthcare provider.

• Normal: Typically under 50 μg/g of stool.
• Borderline/Indeterminate: Around 50–150 μg/g. This gray area may warrant repeat testing.
• Elevated: Above 150–200 μg/g suggests active inflammation is likely present.
• High: Levels above 250–300 μg/g are strongly indicative of significant inflammation.

Note for children: Infants and young children (under age 4) can naturally have higher baseline calprotectin levels, so pediatric reference ranges differ.

What Does It Mean When Calprotectin Is High?

A high fecal calprotectin level is a clear signal of inflammation in the gastrointestinal tract. While it does not diagnose a specific condition, it tells your doctor that an inflammatory process is occurring and requires further investigation. The most common reason for a significantly high calprotectin is Inflammatory Bowel Disease (IBD). However, other causes include:

• Gastrointestinal infections (bacterial, viral, or parasitic)
• Use of nonsteroidal anti-inflammatory drugs (NSAIDs)
• Diverticulitis
• Celiac disease
• Microscopic colitis
• Colorectal cancer (though this is a less common cause)

Can IBS Cause High Calprotectin?

No, IBS by itself does not typically cause high fecal calprotectin. Irritable Bowel Syndrome is classified as a functional disorder, meaning symptoms like abdominal pain, bloating, and altered bowel habits occur without evidence of structural damage or significant inflammation that is detectable by standard tests like calprotectin. Therefore, an elevated calprotectin result strongly suggests that something other than or in addition to IBS is causing the inflammation.

What Cancers Cause High Calprotectin?

While the primary use of the calprotectin test is to screen for inflammatory conditions like IBD, a persistently high level can sometimes be associated with colorectal cancer. It is important to understand that calprotectin is not a test for cancer, but significant inflammation in the colon can be a sign that warrants further evaluation, such as a colonoscopy, to rule out serious conditions. If you have a high calprotectin level, your doctor will consider your overall symptoms, age, and risk factors to determine the appropriate next steps.

How to Treat High Calprotectin in Stool

“Treatment” for high calprotectin is not a one-size-fits-all approach; it focuses on identifying and managing the underlying cause of the inflammation. You should never self-treat based on a calprotectin result alone. The appropriate steps always involve working with a healthcare professional.

1. Consult Your Doctor: Share your results and discuss your symptoms in detail.
2. Undergo Further Testing: Your doctor may recommend a colonoscopy, imaging, or blood tests to pinpoint the cause.
3. Address the Root Cause: If IBD is diagnosed, treatment may include anti-inflammatory medications. If an infection is found, antibiotics or other antimicrobials may be prescribed. For medication-induced inflammation (e.g., from NSAIDs), your doctor may advise alternatives.
4. Monitor Levels: If you have a known condition like IBD, repeated calprotectin tests can help monitor disease activity and treatment effectiveness.

Key Takeaways

• IBS is a functional disorder and does not typically cause high fecal calprotectin.
• Elevated calprotectin is a reliable marker of intestinal inflammation that requires medical evaluation.
• Common causes of high calprotectin include IBD, infections, and certain medications.
• Normal ranges vary by lab and age; always interpret results with your clinician.
• Treatment focuses on the underlying cause, not the calprotectin level itself.

Frequently Asked Questions

What does it mean when calprotectin is high?

A high calprotectin level indicates that there is active inflammation in your intestines. This finding should prompt a discussion with your doctor to determine the cause, which could range from an infection to a chronic condition like IBD.

What is the normal range of calprotectin by age?

For most adults, a normal level is under 50 μg/g. Borderline results fall between 50-150 μg/g, and levels above 150-200 μg/g are considered elevated. Children, especially those under four, have higher normal ranges.

Can stress or diet raise calprotectin?

Stress and diet can trigger IBS symptoms, but they do not typically cause the type of neutrophil-driven inflammation that elevates calprotectin. Symptoms from these triggers are usually due to changes in gut motility and sensitivity.

What should I do if my calprotectin is borderline?

Borderline results can be unclear. Your doctor may suggest repeating the test in a few weeks, especially if you recently had an infection or took NSAIDs, to see if the level normalizes.

Disclaimer: This article is for educational purposes only and is not a substitute for professional medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment plans tailored to your individual health needs.