Laboratory Test Reference Guide

Grape-sized amount required.

When multiple faecal assays are required, each test must have a separate aliquot.

Frozen

< 120 mg/kg 

Testing can only be requested by a SMO and no repeats within 28 days.

• Faecal calprotectin is a marker of intestinal mucosal inflammation that can be useful in differentiating between irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD) in symptomatic patients. In IBD, levels correlate with disease activity and a concentration <50 μg/g is considered to be a good negative predictor (published negative predictive values 70-90%) and to help triage patients for colonoscopy. Levels >50 μg/g are associated with a risk of relapse.

Indications and referral criteria:

• In patients presenting with diarrhoea, first line tests to exclude pathology may include CBC, CRP, ferritin, TFTs, stool culture and ova and parasites if travel history.
• Faecal calprotectin is a second line investigation if there is a concern about possible IBD, although may be a first line investigation if there is a family history of IBD. It may be particularly helpful in paediatric IBD when other investigations may be normal.
• In the presence of “red flags” (e.g. unexplained iron deficiency anaemia, rectal bleeding, weight loss or family history of colon cancer), faecal calprotectin testing may incur unnecessary delay in referral to a gastroenterologist and especially where there is likely consideration for colonoscopy.