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
Lothian data support use of calprotectin in those aged <50 BUT a cut off of age <40 has been used to align with NHS Scotland/HIS guidelines
| <50 µg/g | NORMAL- TREAT as IBS (see separate guidance) |
| Between 50 and 150 µg/g | EQUIVOCAL (see below) |
| >150 µg/g | ABNORMAL- REFER to GI for further assessment |
EQUIVOCAL
Time frame for repeat fecalcalprotectin is at least 4 weeks (Oct 2018)
- If the repeat is <50 treat as normal
- If the repeat remains equivocal or is rising, treat as abnormal (REFER to GI)
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.
Faecal calprotectin is most useful in those under the age of 50 and in the following situations
Recent onset lower GI symptoms e.g.
- Cramping lower abdominal pain
- Predefecatory pain
- Lower abdominal bloating
- Looser or more frequent stools
- Harder or less frequent stools
- Passing mucus PR
- Passing blood PR
- Bloody diarrhoea
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
Interpretation of results
Lothian data support use of calprotectin in those aged <50 BUT a cut off of age <40 has been used to align with NHS Scotland/HIS guidelines
- <50 µg/g NORMAL- TREAT as IBS (see separate guidance)
- Between 50 and 150 µg/g EQUIVOCAL (see below)
- >150 µg/g ABNORMAL- REFER for further assessment
EQUIVOCAL results Time frame for repeat fecalcal protectin is at least 4 weeks (Oct 2018)
- If the repeat is <50 treat as normal
- If the repeat remains equivocal or is rising, treat as abnormal (REFER)
