Director, Department of Gastroenterology, University Hospital of Santiago de Compostela, Spain
Consultant Gastroenterologist, Royal Hallamshire Hospital and University of Sheffield, UK
Several tests are available to diagnose PEI, which vary in their robustness and cost.1 Although invasive tests are the most direct and sensitive methods for assessing pancreatic exocrine function, their cost and invasive nature limit their routine use in clinical practice.1
Non-invasive tests have gained popularity in the clinical setting. Further detail of these tests is given below.
Faecal elastase screening for pancreatic function
This measures the amount of the pancreatic exocrine elastase-1 enzyme in the stool.2,3
It requires a single stool sample and is relatively simple to perform, making this test popular in clinical practice.2
Faecal elastase-1 levels are quantified with an ELISA*1
Levels of faecal elastase-1 have been shown to correlate with the flow rate of pancreatic enzymes5
- Various imaging techniques such as endoscopic ultrasound, magnetic resonance imaging or computed tomography are now available to detect early pancreatic disease6
Co-efficient of fat absorption is calculated from a 72-hour faecal fat quantification1
Patients keep to a strict diet of 100g fat/day for 3-5 days
Total quantity of faeces excreted during 3 days are collected and pooled for analysis
Steatorrhoea is present if the percentage of ingested fat subsequently excreted is:
>7% in patients over 6 months of age
>15% in patients under 6 months of age
The odious nature of this test makes it very unpopular with both patients and laboratory technicians, and it does not distinguish between pancreatic and nonpancreatic causes.1
How the breath test works
In chronic pancreatitis, sensitivity of the faecal elastase-1 test for diagnosing PEI varies from 0–63% in mild-to-moderate cases to 77–100% in moderate-to-severe cases of PEI.
Smith RC, et al. 20151
- Smith RC, Smith SF, Wilson J, Pearce C, Wray N, Vo R, et al. Australasian guidelines for the management of pancreatic exocrine insufficiency. Australasian Pancreatic Club, October 2015. pp 1-122.
- Sikkens EC, Cahen DL, Kuipers EJ, et al. Pancreatic enzyme replacement therapy in chronic pancreatitis. Best Pract Res Clin Gastroenterol. 2010;24:337-47.
- Leeds JS, Oppong K, Sanders DS. The role of fecal elastase-1 in detecting exocrine pancreatic disease. Nat Rev Gastroenterol Hepatol. 2011;8:405-15.
- Thomas PD, Forbes A, Green J, et al. Guidelines for the investigation of chronic diarrhoea, 2nd edition. Gut. 2003;52(Suppl 5):v1-15.
- Bian Y, Wang L, Chen C, Lu JP, Fan JB, Chen SY, et al. Quantification of pancreatic exocrine function of chronic pancreatitis with secretin-enhanced MRCP. World J Gastroenterol. 2013;19(41):7177-82.
- Choueiri NE, Balci NC, Alkaade S, et al. Advanced imaging of chronic pancreatitis. Curr Gastroenterol Rep. 2010;12:114-20.
- Domínguez-Muñoz JE. Pancreatic exocrine insufficiency: diagnosis and treatment. J Gastroenterol Hepatol. 2011;26(Suppl 2):12- 16.