What a calprotectin result can show
The same result can mean different things when checking new symptoms or following known IBD. Age, infection, medicines, and the lab method also matter. A high result shows inflammation may be present, but it doesn't name the cause.
Inflammation test
A high result can have many causes
IBD, infection, celiac disease, colorectal cancer, medicines, bleeding, and other problems can raise it.
Different reasons for testing
Screening and monitoring use different rules
A first check of bowel symptoms is read differently from known Crohn's disease, an ulcerative-colitis flare, or follow-up after surgery.
Assay and sample
Results differ by lab and sample
Lab tests use different bands. Sampling, medicines, infection, storage, and which part of the stool was collected can change the result.
This result alone can't diagnose IBD, IBS, infection, cancer, leaky gut, changes in gut bacteria, food sensitivity, SIBO, or a cause of brain fog. Use it to choose the next test, not to create a new label.
Save this test
Save the result with the reason for testing
Keep the stool result with symptoms, medicines, recent infection, warning signs, and the next test.
Bring this record to the next appointment so the result can be read in context.
What can change the meaning of a calprotectin result
Age, pregnancy, where the bowel is inflamed, medicines, infection, cancer risk, and known IBD all change what the result means. There are no general male and female cutoffs.
Babies and young children
Healthy babies can have higher and less steady levels than older children and adults, so adult cutoffs may not fit. A 2026 study couldn't use calprotectin to tell food-protein allergic proctocolitis from healthy babies of the same age. Blood in the stool, poor feeding, fever, extreme sleepiness, vomiting, dehydration, or poor growth needs a child's doctor.
Older children and teenagers
Calprotectin can help check for IBD, but growth, weight, puberty, pain, diarrhea, blood, mouth sores, joint or skin symptoms, anemia, CRP, and infection tests still matter. A specialist may also use endoscopy or scans. Use child ranges and the same lab method for repeat tests.
Pregnancy
Pregnancy doesn't seem to raise calprotectin the way it changes some blood tests, so calprotectin can help follow known IBD. New bleeding, severe pain, diarrhea that does not stop, dehydration, fever, less fetal movement, or another pregnancy warning sign needs direct care.
Men and women
Most labs use the same adult bands for men and women. Symptoms, blood from a period or the rectum getting into the sample, infection, medicines, IBD history, family history, anemia, and cancer risk matter more.
Adults aged 50 and older
This test doesn't replace FIT, an exam, colonoscopy, or a cancer referral. New bleeding, iron-deficiency anemia, weight loss, or a lasting change in bowel habits needs its own check. So does a family history of colorectal cancer, even when calprotectin is low.
Before collecting the stool sample
Ask why you're having the test. It may check new bowel symptoms, possible IBD, known Crohn's disease or ulcerative colitis, a possible flare, treatment response, or recovery after surgery. Each reason may use a different cutoff.
Use the collection kit and return instructions from the lab. Keep stool away from toilet water, urine, cleaners, and menstrual blood. Put in only the amount asked for, close and label the container, wash your hands, and store or return it as directed.
You usually don't need to fast. Eat and drink as usual unless another test says not to. Do not try to bring on symptoms, eat a problem food on purpose, start a strict diet, or change IBD care to change the result.
List ibuprofen, naproxen, diclofenac, aspirin, other NSAIDs, proton-pump inhibitors (stomach-acid medicines), antibiotics, steroids, biologics, immune medicines and bowel-prep products. Keep taking prescribed medicines unless the doctor gives you a plan to stop.
Mention recent diarrhea, vomiting, fever, travel, sick contacts, antibiotics, a positive stool-infection test, colonoscopy, surgery, gut bleeding, and when symptoms began. Infection and several other conditions can raise calprotectin.
Tell the doctor at once about red or black stool, severe or worsening stomach pain, repeated vomiting, severe illness with fever, dehydration, or fainting. Also report fast weight loss, a swollen belly, trouble passing stool or gas, or a child who isn't growing. Get care without waiting for this test.
Name the reason for testing
Ask whether this is the first check of bowel symptoms or a check of known IBD, a possible flare, treatment response, or recovery after surgery.
Collect a clean stool sample
Use the kit from the lab. Keep the sample out of toilet water and urine. Take the amount asked for, label it, and follow the storage and return-time rules.
Save the assay and context
Save the value, mcg/g unit, report range, lab, test method if shown, date, and stool form. Add recent infections, medicines, symptoms, and whether this is the first or a repeat test.
Ask what the doctor wants to check next
The next check may be CBC, CRP, iron tests, celiac tests, stool infection tests, FIT, colonoscopy with biopsy, or a scan of the small bowel. The choice depends on age, symptoms, warning signs, and whether IBD is already known.
How to read a fecal calprotectin result
Start with the reason for testing and any warning signs. Then check infection, medicines, the lab band, age, where disease may be, and which test comes next.
Within the lab range
Within your lab's range for the test method, age, symptoms, and reason for testing
Active gut inflammation is less likely. Still check warning signs and symptoms because calprotectin can miss some types or places of IBD.
Borderline or difficult to compare
Inside the laboratory's borderline or indeterminate band, or difficult to compare because infection, medicines, age, assay, collection, or the reason for testing is unclear
Review symptoms, warning signs, infection tests, pain and stomach medicines, and IBD treatment. The doctor may repeat the same test after a set time or order another test right away if the concern is higher.
High and needs the cause found
Above your lab's range or above the cutoff used by your IBD check or care plan
Gut inflammation is more likely, but this result doesn't name the disease. The next step may be infection tests, a gut specialist, endoscopy with biopsy, or a scan. A checked result may also change a known-IBD plan.
The cutoff depends on the care plan
Mayo uses below 50, 50 through 120, and above 120 mcg/g. The AGA uses 150 mcg/g for some people with known Crohn's disease and under 50 after surgery in a narrow care plan. Other services use 100, 200, or 250 for repeat tests or referrals. Save the number, unit, lab method, symptoms, and reason before using a cutoff.
See research details
The details below explain lab bands, IBD cutoffs, medicine effects, cancer risk in older adults, and limits in children.
Mayo says borderline results may reflect mild inflammation or NSAID, aspirin, or proton-pump-inhibitor exposure and suggests a 4 to 6 week repeat when clinically appropriate. These are Mayo's bands, not a universal IBD diagnosis rule.
The same guidance recommends endoscopy in several situations where symptoms and test results disagree. It uses under 50 mcg/g for a narrow postoperative-remission pathway. Neither number is a general screening target.
The 2025 ACG Crohn's guideline and the ACG ulcerative-colitis update base diagnosis and treatment on clinical assessment, endoscopy, imaging, biopsy, and other tests. Neither relies on one stool number.
Performance changes with threshold, assay, population, symptoms, and disease location. Infection, celiac disease, colorectal cancer, and other causes of intestinal neutrophil activity can also raise the result.
Above 50 mcg/g had 93.8 percent sensitivity for IBD in the older group, but positive predictive value was only 12.8 percent. FIT outperformed a 150 mcg/g calprotectin threshold for organic pathology including colorectal cancer. New bleeding, anemia, weight loss, or later-life bowel change needs more than calprotectin alone.
Association does not prove that a medicine caused one person's result. Mention the exact medicine and timing, then ask whether the reason for testing allows a safe review or repeat. Keep taking prescribed treatment unless its prescriber gives different instructions.
Use the same lab and method for trends when possible. Keep collection and transport details with the number. Results from different kits aren't directly comparable.
If IBD or another bowel disease is confirmed, pain, poor sleep, anemia, iron or B12 deficiency, dehydration, active inflammation, medicines, and eating less may each affect thinking. Test and treat those factors directly. Calprotectin isn't a score for brain fog.
What you can do while the bowel problem is checked
Collect the sample correctly, notice what changed, and follow the next testing step. Warning signs need care without delay, whatever one stool number says.
Notice what changed
Notice how often you pass stool and what it looks like. Note blood, mucus, waking at night to go, urgency, pain, fever, weight, appetite, vomiting, travel, sick contacts, food changes, medicines, and missed IBD doses. Also check thinking, sleep, fluids, and meals.
Keep up food and fluids
During diarrhea, follow the food and fluid plan from your care team. Get help if you can't keep fluids down or make very little urine. Do not start fasting, a cleanse, or a strict low-FODMAP, gluten-free, low-histamine, or IBD diet because of this result. Cutting out many foods can worsen weight loss and poor nutrition.
Review medicines without stopping them
List NSAIDs, aspirin, stomach-acid medicines, antibiotics, steroids, biologics, immune medicines, and supplements. Ask which could affect the test and whether a repeat would help. Check with the prescriber before changing heart, pain, stomach, or IBD medicine.
Follow the confirmed condition, not the marker alone
If you have IBD, take treatment as agreed and report flare symptoms early. If not, ask how the team will check infection, celiac disease, anemia, colorectal bleeding or cancer risk, and changes in the bowel. Do not buy probiotics, enzymes, binders, or supplements just to lower the number.
Get urgent help for heavy bleeding, black stool, fainting, severe or fast-worsening stomach pain, a hard or swollen belly, or repeated vomiting. Trouble passing stool or gas, high fever with severe illness, severe dehydration, or sudden severe weakness also needs urgent help. A child with poor growth, lasting blood in the stool, severe pain, fever, dehydration, or extreme sleepiness needs prompt care. Get help without waiting for a repeat test.
What to save before the next appointment
Keep these together
- Value, mcg/g unit, report range, lab method, date, stool form, storage and return time, and first or repeat test
- Reason for testing: new symptoms, possible or known IBD, possible flare, treatment response, or follow-up after surgery
- Bowel habits, blood or mucus, night symptoms, urgency, pain, fever, vomiting, appetite, weight, fluids, travel, sick contacts, infection results, and when symptoms began
- Medicines and supplements, pregnancy or recent birth, age, sex, and any period blood or urine in the sample
- CBC, CRP, iron tests, celiac tests, FIT, infection tests, endoscopy, biopsy, scans, diagnosis, treatment, repeat date, and when to seek care
Question for the visit
“Which lab method and care plan apply? Could infection, medicines, age, the place of inflammation, or collection explain the result? What test will finish this check?”
Sources for Fecal Calprotectin Stool Test
Guide sections: Mayo's test has three bands; High results aren't unique to IBD; Men and women; Review medicines without stopping them
Guide sections: Known Crohn's disease has its own cutoffs
Guide sections: Current U.S. guidelines make calprotectin one part of IBD care; Notice what changed
Guide sections: Calprotectin doesn't explain brain fog; Notice what changed; Keep up food and fluids
Guide sections: Older children and teenagers; Adults aged 50 and older
Faecal Calprotectin Test.
Guide sections: Keep up food and fluids
Inflammatory bowel disease clinical prioritisation criteria.
ACG Clinical Guideline Update: Ulcerative Colitis in Adults.
ACG Clinical Guideline: Management of Crohn's Disease in Adults.
British Society of Gastroenterology guidelines on inflammatory bowel disease in adults: 2025.
Expert recommendations regarding the use of fecal calprotectin in daily clinical practice: statements of a taskforce process from the Hellenic Group for the Study of Inflammatory Bowel Disease (EOMIFNE).
Prescription of NSAIDs and proton pump inhibitors are associated with increased faecal calprotectin levels in patients with functional bowel disorder: an observational study.
Systematic review with meta-analysis: Diagnostic performance of faecal calprotectin in distinguishing inflammatory bowel disease from irritable bowel syndrome in adults.
International consensus on methodological issues in standardization of fecal calprotectin measurement in inflammatory bowel diseases.
The Use of Fecal Calprotectin Testing in Paediatric Disorders: A Position Paper of the European Society for Paediatric Gastroenterology and Nutrition Gastroenterology Committee.
Fecal Calprotectin Is Not Affected by Pregnancy: Clinical Implications for the Management of Pregnant Patients with Inflammatory Bowel Disease.
Fecal calprotectin and other biomarkers are not prospectively associated with food protein-induced allergic proctocolitis.
Evaluating the role of faecal calprotectin in older adults: a retrospective observational study.
See each claim's sources
range
Mayo's named assay reports under 50 mcg/g as normal, 50 to 120 as borderline, and over 120 as abnormal, while warning that normal results do not exclude IBD and elevated results are not diagnostic of IBD.interpretation
AGA uses a 150 mcg/g fecal-calprotectin threshold in selected known-Crohn's monitoring pathways and under 50 mcg/g in a narrow postoperative context, not as universal diagnostic cutoffs.indication
The 2025 ACG ulcerative-colitis guideline recommends fecal calprotectin for assessing response, suspected relapse, and maintenance, while current Crohn's and ulcerative-colitis guidance keeps diagnosis and treatment tied to the wider clinical pathway.limitation
Fecal calprotectin reflects neutrophil-driven intestinal inflammation and can rise with IBD, gastrointestinal infection, celiac disease, colorectal cancer, and other inflammatory conditions; it does not identify the cause by itself.context
A 2026 study of 669 adults found that above 50 mcg/g had 93.8 percent sensitivity for IBD in adults aged 50 or older but only 12.8 percent positive predictive value, and FIT performed better for broader organic pathology including colorectal cancer at the compared threshold.context
NSAIDs, aspirin, and proton-pump inhibitors can be associated with higher fecal-calprotectin results and belong in interpretation, without proving that a medicine caused one person's result.context
Pediatric guidance calls for age-aware local ranges and consistent methods, and a 2026 prospective study found fecal calprotectin did not distinguish food-protein allergic proctocolitis from healthy age-matched infants.context
Available IBD research indicates pregnancy itself does not raise fecal calprotectin in the same way it changes some blood markers, so the stool marker can remain useful inside pregnancy IBD care.procedure
A stool sample should be collected with the supplied kit without toilet-water or urine contamination and returned or stored under the performing laboratory's instructions.limitation
Fecal-calprotectin guidelines do not validate the result as a diagnosis of the cause of brain fog, leaky gut, dysbiosis, food sensitivity, histamine intolerance, or SIBO.