Can Hemorrhoids Elevate Calprotectin?
Yes, hemorrhoids can cause false elevations in fecal calprotectin levels due to local bleeding and inflammation, potentially confounding the interpretation of this biomarker when evaluating for inflammatory bowel disease. 1
Mechanism of Elevation
Hemorrhoids can elevate fecal calprotectin through:
- Local bleeding that introduces blood-derived neutrophils into the stool sample 1
- Local inflammatory response at the hemorrhoidal tissue site 1
- Contamination of the stool sample with blood from hemorrhoidal bleeding 1
Clinical Implications for Interpretation
When encountering elevated calprotectin in a patient with known or suspected hemorrhoids:
For patients with mild symptoms and calprotectin >150 μg/g:
- Endoscopic assessment is recommended rather than empiric IBD treatment adjustment 1, 2
- This approach helps differentiate true intestinal inflammation from hemorrhoid-related elevation 1
- The false positive rate in this intermediate probability scenario is 15.5% 2
For patients with moderate to severe symptoms and calprotectin >150 μg/g:
- Calprotectin >150 μg/g reliably suggests moderate to severe endoscopic inflammation with only a 4.6% false positive rate 1, 2
- In this scenario, hemorrhoids are less likely to be the sole cause of elevation 1
Other Conditions That Elevate Calprotectin
Hemorrhoids should be considered alongside other non-IBD causes of elevated calprotectin:
- Infectious gastroenteritis (calprotectin will not discriminate between IBD and gastroenteritis in acute diarrhea) 3, 4
- Colorectal cancer (median 53.4 mg/L) 4
- NSAID use within the past 6 weeks 1
- Gastric carcinoma (median 30 mg/L) 4
Practical Approach to Patients with Hemorrhoids
When hemorrhoids are present:
- Patients presenting with blood in the stool should be evaluated for multiple causes, including hemorrhoids, before attributing elevated calprotectin solely to IBD 1
- Consider the clinical context: alarm symptoms such as rectal bleeding or abdominal pain require cancer pathway referral regardless of calprotectin result 2
- Repeat calprotectin measurement may be valuable, as 53% of patients with initially elevated calprotectin (≥100 μg/g) showed reduction after approximately 18 days 3
Key Caveats
- Calprotectin is a sensitive but not specific marker of intestinal inflammation 5
- The sensitivity of calprotectin for detecting endoscopically active disease is 90.6% at a cut-off of 50 μg/g, but specificity improves at higher thresholds 2
- Bloody diarrhea warrants flexible sigmoidoscopy regardless of calprotectin result to directly visualize the source of bleeding 3
- Calprotectin is not sensitive enough to exclude colorectal cancer, so cancer pathway referral should be strongly considered in patients with alarm symptoms 2, 3