Fecal Lactoferrin: What a Positive Result Means

Fecal lactoferrin is a stool test that helps show whether inflammation is present in your intestines. Lactoferrin is an iron-binding protein released mainly by neutrophils, a type of white blood cell that gathers in the gut wall during inflammation. When the intestinal lining is irritated or inflamed, these cells shed lactoferrin into the stool, where a laboratory can measure it. Because of this, the test acts as a marker of intestinal inflammation rather than a test for one specific disease. In this article you will learn what fecal lactoferrin is, what a positive or negative result may mean, how it compares with fecal calprotectin, what can affect the reading, and what steps a clinician may take next.

What fecal lactoferrin is and what the test measures

Lactoferrin is a protein found inside neutrophils, the white blood cells that respond quickly to infection and tissue damage. When inflammation develops in the digestive tract, neutrophils migrate into the bowel wall and release their contents, including lactoferrin. Some of this protein ends up in the stool, so its level reflects how many of these inflammatory cells are active in the intestine.

The test uses a small stool sample, usually collected at home in a container provided by the clinic or laboratory. Lactoferrin is fairly stable in stool, which makes it practical to transport and analyze. The result tells your clinician whether neutrophil-driven inflammation is likely, but it does not point to a single cause on its own.

There are two main ways to report the result. A qualitative test gives a simple positive or negative answer, sometimes available as a rapid in-office check. A quantitative test reports an actual number, often in micrograms of lactoferrin per gram of stool, which can help track changes over time. Your laboratory decides which method it uses and sets its own reference range.

What a positive or elevated fecal lactoferrin result means

A positive or elevated fecal lactoferrin result generally suggests that inflammation is present somewhere in the intestines. It signals that neutrophils have been active in the gut, which can happen in several conditions. Importantly, the test flags inflammation; it does not name the exact disease behind it.

Possible reasons for an elevated result include inflammatory bowel disease such as Crohn’s disease or ulcerative colitis, an invasive bacterial infection, or another inflammatory process in the bowel. Because several conditions can raise the level, your clinician interprets the result alongside your symptoms, medical history, and other tests rather than in isolation.

A higher reading does not automatically mean a serious illness. Sometimes a recent infection raises the level for a while, and a repeat test later may return to normal. The number is one clue in a larger picture, not a diagnosis by itself.

What a negative or normal result means

A negative or normal fecal lactoferrin result makes significant neutrophil-driven inflammation in the intestines less likely. In the right setting, this can support the idea that symptoms come from a non-inflammatory cause, such as irritable bowel syndrome, especially when the rest of the evaluation fits that picture.

No stool test is perfect, however. Some people with early or mild inflammatory bowel disease can still have a low or borderline reading, and white blood cells can break down in a sample, which may lower the measured level. If your symptoms are persistent, severe, or changing, your clinician may still recommend further testing even when the result looks normal.

The main use: telling inflammatory from non-inflammatory diarrhea

The most valuable role of fecal lactoferrin is helping separate inflammatory causes of diarrhea from non-inflammatory ones. This distinction matters because the two groups are managed very differently, and it can guide whether more invasive testing is needed.

Inflammatory causes include inflammatory bowel disease and certain invasive bacterial infections, which tend to raise lactoferrin because neutrophils flood the gut wall. Non-inflammatory causes, such as irritable bowel syndrome, usually do not produce that neutrophil response, so lactoferrin often stays low. A clear result in either direction helps your clinician decide how urgently to investigate and whether a colonoscopy may be warranted.

People who want to understand related stool testing often review our guide to our fecal calprotectin test guide. Those exploring functional bowel symptoms may also read our overview of our irritable bowel syndrome guide.

Monitoring known inflammatory bowel disease

Beyond initial evaluation, fecal lactoferrin can help monitor people who already have a diagnosis of inflammatory bowel disease. Because the level tends to rise when intestinal inflammation increases, repeat testing can give clinicians a non-invasive way to follow disease activity between visits.

In practical terms, a falling level alongside improving symptoms may suggest that inflammation is settling, while a rising level can prompt a closer look. The test does not replace endoscopy when a direct view of the bowel is needed, but it can help decide who is more likely to benefit from further investigation. Readers managing Crohn’s disease can consult our detailed our Crohn’s disease overview for background on long-term care.

Fecal lactoferrin vs fecal calprotectin

Fecal lactoferrin and fecal calprotectin are closely related. Both are proteins released by neutrophils, so both mark neutrophil-driven inflammation in the gut, and both are used to help separate inflammatory from non-inflammatory bowel conditions. They are often discussed together, and some clinicians use one or the other based on local laboratory availability and experience.

Fecal calprotectin is the more widely used and studied of the two, with broad reference ranges and extensive guideline support. Fecal lactoferrin offers similar information and may be reported qualitatively for a faster answer. The table below compares the two markers at a glance.

What can affect fecal lactoferrin results

Several factors can influence a fecal lactoferrin reading, which is why clinicians look at the whole clinical picture. Understanding these influences helps explain why a single number is interpreted with care.

• Breastfed infants can have higher lactoferrin levels because human milk naturally contains the protein, so pediatric interpretation uses age-specific guidance.
• Blood in the stool sample may affect the reading, since blood can carry white blood cells and their proteins.
• Timing and sample handling matter, because white blood cells can break down over time and lower the measured level.
• A recent intestinal infection can raise the level temporarily, even after symptoms ease.
• Certain medicines, including nonsteroidal anti-inflammatory drugs, can irritate the gut lining in some people.

Because of these influences, a borderline or unexpected result is sometimes repeated after a short interval. Your clinician may also ask about recent illnesses and medications before drawing conclusions.

What a positive result does and does not tell you

It helps to be clear about the limits of this test. A positive fecal lactoferrin result tells you that inflammation is likely present in the intestines and that a non-inflammatory explanation is less probable. That information can be genuinely useful for deciding next steps.

What it does not tell you is the specific disease, the exact location of the inflammation, or how severe the underlying condition is. The same elevated result could come from inflammatory bowel disease, an invasive infection, or another inflammatory process. For that reason, a positive test is a signal to investigate further, not a final answer. People comparing inflammation markers in blood may also review our explainer on our C-reactive protein marker guide.

Next steps a clinician may take

What happens after a fecal lactoferrin result depends on the number, your symptoms, and your history. The test is designed to guide decisions rather than to stand alone.

If the result is normal and symptoms are mild, your clinician may reassure you, treat symptoms, and watch for change. If the result is elevated, especially with warning signs, they may order additional stool studies, blood tests, or imaging, and may refer you to a gastroenterologist. When inflammatory bowel disease or another structural problem is suspected, a colonoscopy may be recommended to look directly at the bowel and take tissue samples. Readers who notice changes in their bowel habits may find our guide to our stool consistency guide helpful background, and those evaluating digestion problems can read our overview of our fatty stool guide.

متى يجب زيارة الطبيب

See a clinician promptly if you have ongoing bowel symptoms along with any concerning feature, because these can point to inflammation or bleeding that needs evaluation.

• Diarrhea that lasts more than a few days or keeps returning
• Blood in the stool, or black, tarry stool
• فقدان الوزن غير المبرر
• Fever with diarrhea
• Severe or worsening abdominal pain
• Waking from sleep to pass stool
• Signs of anemia, such as unusual tiredness or pale skin

Seek urgent care if you have severe abdominal pain, signs of dehydration, fainting, persistent vomiting, or heavy rectal bleeding. If you are pregnant, have a weakened immune system, or are caring for a young child, follow up sooner so the result can be interpreted in context. Those who want to understand other dark-stool changes can read our guide to our black specks in stool guide.

مسرد المصطلحات الرئيسية

الأسئلة الشائعة

What is fecal lactoferrin and what does the test check for?

Fecal lactoferrin is an iron-binding protein released by neutrophils, a type of white blood cell. The stool test checks for intestinal inflammation by measuring how much of this protein is present. A higher amount suggests that inflammatory cells are active in the gut.

What does a positive fecal lactoferrin result mean?

A positive result suggests that inflammation is present somewhere in the intestines. It can occur with inflammatory bowel disease or an invasive bacterial infection, among other causes. It flags inflammation but does not identify a specific disease, so your clinician interprets it with your symptoms and other tests.

Fecal lactoferrin vs calprotectin, what is the difference?

Both are proteins released by neutrophils and both mark gut inflammation, so they give similar information. Calprotectin is the more widely used and studied marker, while lactoferrin may be reported as a simple positive or negative result. Clinicians often choose one based on laboratory availability and experience.

Is fecal lactoferrin positive in C. diff or E. coli infection?

Invasive bacterial infections that inflame the gut, such as some forms of Clostridioides difficile or invasive E. coli illness, can raise fecal lactoferrin because they trigger a neutrophil response. The test cannot identify the organism, so specific stool tests are still needed to confirm the cause.

Is there a treatment for a positive fecal lactoferrin result?

There is no treatment for the marker itself, because it is a signal rather than a disease. Care focuses on finding and treating the underlying cause, whether that is inflammatory bowel disease, an infection, or another condition. Once the cause is treated, the level often falls.

Can diet or medications affect the result?

Yes. A recent intestinal infection, certain medicines such as nonsteroidal anti-inflammatory drugs, blood in the sample, and sample timing can all influence the reading. In breastfed infants, levels can be higher because human milk contains lactoferrin. Tell your clinician about recent illnesses and medications.

أحدث التطورات العلمية

The points below draw on recent peer-reviewed research indexed in PubMed. A promising finding is not the same as established care, and none of this should change your own treatment without a clinician’s guidance.

According to PubMed, a 2025 comparative study in Cureus measured fecal lactoferrin in 50 patients with inflammatory bowel disease, 25 with irritable bowel syndrome, and 25 healthy controls. Levels were far higher in the inflammatory bowel disease group, and at the chosen cutoff the test showed 88% sensitivity and 84% specificity for telling the two conditions apart, with an area under the curve of 0.908, which the authors described as excellent diagnostic performance. It was a single-center study and the authors called for larger trials to confirm the findings (Jubaere and colleagues, 2025) DOI.

According to PubMed, a 2023 American Gastroenterological Association clinical practice guideline in Gastroenterology reviewed the evidence for fecal calprotectin, fecal lactoferrin, and blood C-reactive protein as non-invasive markers in ulcerative colitis. The expert panel suggested that, in people in symptomatic remission, a normal fecal lactoferrin together with a low calprotectin and normal C-reactive protein can help rule out active inflammation and avoid routine endoscopy, while elevated markers in people with moderate to severe symptoms can inform treatment decisions. These were conditional recommendations based on a structured evidence review (Singh and colleagues, 2023) DOI.

According to PubMed, a 2023 prospective study in Cancers evaluated a point-of-care stool test combining four markers, including lactoferrin and calprotectin, in 571 patients with gastrointestinal symptoms. When all four markers were negative, the negative predictive value was 100% for colorectal cancer or inflammatory bowel disease, and the combined test helped identify patients who could safely avoid an unnecessary colonoscopy. The authors noted this approach could help prioritize higher-risk patients (Hijos-Mallada and colleagues, 2023) DOI.

مصادر

• White Blood Cell (WBC) in Stool — MedlinePlus, National Library of Medicine
• Inflammatory bowel disease (IBD): Diagnosis and treatment — Mayo Clinic
• AGA Clinical Practice Guideline on the Role of Biomarkers for the Management of Ulcerative Colitis — Gastroenterology, 2023 (Singh et al.) — DOI
• Diagnostic Value of Fecal Lactoferrin in Differentiating Inflammatory Bowel Disease From Irritable Bowel Syndrome — Cureus, 2025 (Jubaere et al.) — DOI
• A Point-of-Care Faecal Test Combining Four Biomarkers — Cancers, 2023 (Hijos-Mallada et al.) — DOI

للمزيد من القراءة

• الكالبروتكتين البرازي: فهم نتائج الاختبار
• اختبار البراز للكشف عن البويضات والطفيليات: فهم النتائج
• متلازمة القولون العصبي: كيفية التعامل معها
• Crohn’s disease: causes, symptoms, and treatments
• البروتين التفاعلي C (CRP): فهم هذا المؤشر الالتهابي

Making sense of fecal lactoferrin is easier when you see it alongside the other results that describe your gut, such as a fecal calprotectin test, a stool white blood cell test, a stool culture, or a C-reactive protein blood test. Read together, these results help paint a clearer picture of whether inflammation is driving your symptoms. AI DiagMe helps you understand what your stool and inflammation results may mean in plain language so you can ask better questions. It is a tool to help you understand your results; it does not diagnose conditions and does not replace your doctor.

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