Makindo Medical Notes

Used as a diagnostic test between Irritable Bowel Syndrome (IBS) and Inflammatory Bowel Disease (IBD). An elevated level can suggest inflammatory bowel disease.

Usage

• Patients with suspected inflammatory bowel disease and no red flags
• Patients aged 18-60 years presenting with lower gastrointestinal symptoms
• IBS or IBD is suspected but there is diagnostic uncertainty
• Do not use if colorectal cancer or acute severe IBD are suspected
• If symptoms of ovarian cancer are suspected, CA125 should be measured

Aetiology

• Calprotectin is a stable protein that accounts for about 60% of neutrophil cytosolic protein.
• Calprotectin is released into the faeces when neutrophils gather at the site of any gastrointestinal tract inflammation.
• Faecal calprotectin is a very sensitive measure of intestinal inflammation.

Raised Levels

• Inflammatory Bowel Disease (IBD)
• Infective colitis
• Diverticulitis
• Certain drugs (e.g., NSAIDs)
• Colorectal cancer

Cautions

• Treatment with NSAIDs may increase a patient's faecal calprotectin by approximately twofold.
• NSAIDs, such as aspirin or ibuprofen, should be stopped for 4 weeks prior to collecting a sample.

Terminology

• IBS: Irritable Bowel Syndrome
• IBD: Inflammatory Bowel Disease

Assessment

• Initial faecal calprotectin <100 microgram/g: IBD unlikely.
  • Treat as IBS with a 6-week review.
  • If symptoms persist and >50 micrograms/g, refer routinely to gastroenterology.
  • Consider non-gastrointestinal causes (e.g., urogynaecological disease).
• Initial faecal calprotectin 100-250 microgram/g:
  • Repeat faecal calprotectin within 4 weeks, as levels may normalize.
  • If repeat FC >250, refer urgently to gastroenterology.
  • If repeat FC 100-250, refer routinely to gastroenterology.
  • FC <100: Treat as IBS.
• Initial faecal calprotectin >250 microgram/g:
  • Review clinically in primary care.
  • Urgent gastroenterology referral if symptoms worsen.
  • Repeat faecal calprotectin to confirm levels.

Sample Requirements

• 1-5 g faeces collected into a stool collection pot.
• Values below 150 micrograms/g of faeces suggest IBS.
• Values above 150 micrograms/g of faeces suggest IBD.

Advice for Patients

• How to collect a stool sample for faecal calprotectin analysis (PDF)