Faecal calprotectin testing is recommended by NICE as an option to help distinguish between inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis, and non-inflammatory bowel diseases, such as irritable bowel syndrome.

Faecal calprotectin is a substance that is released into the intestines in excess when there is any inflammation there.

Interpretation of Faecal Calprotectin Results

​<50 µg/g NORMAL- TREAT as IBS
Between 50 and 150 µg/g EQUIVOCAL (see below)
>150 µg/g ABNORMAL- REFER to GI for further assessment

 

EQUIVOCAL

Time frame for repeat faecal calprotectin is at least 4 weeks

  • If the repeat is <50 treat as normal
  • If the repeat remains equivocal or is rising, treat as abnormal (REFER to GI)

Notes

Faecal calprotectin will be elevated with infective colitis as well as active IBD

If the symptoms suggest infective gastroenteritis delay any faecal calprotectin testing by 2 weeks

NSAID use and alcohol can give false positives

 

Many people with irritable bowel syndrome have unnecessary invasive hospital investigations before their condition is diagnosed. Using faecal calprotectin testing will mean most people with irritable bowel syndrome can be diagnosed without the need for these investigations.

Supporting clinical decision making

  • Differentiating Irritable Bowel Syndrome (IBS) from Inflammatory Bowel Diseases (IBD)

Monitoring disease activity in known IBD

  • Efficacy of drug therapy or guiding changes to drug therapy

Editorial Information

Author(s): Jonathan Fletcher, Angus Wallace.

Author email(s): bor.gastroenterology@borders.scot.nhs.uk.