A prospective, comparative study of the para-aminobenzoic acid test and faecal elastase 1 in the assessment of exocrine pancreatic function

Aliment Pharmacol Ther. 2003 Feb;17(3):467-71. doi: 10.1046/j.1365-2036.2003.01451.x.


Background: The assessment of exocrine pancreatic insufficiency is part of the routine work-up of patients with persistent diarrhoea or suspected steatorrhoea. Direct and indirect tests for the diagnosis of exocrine pancreatic insufficiency have their drawbacks. Measurement of faecal elastase 1 by enzyme-linked immunoabsorbent assay is a simple, non-invasive, robust test for exocrine pancreatic insufficiency.

Methods: We performed a prospective comparison of the para-aminobenzoic acid test and faecal elastase 1 test in 45 patients being investigated for diarrhoea or suspected steatorrhoea. Details of clinical suspicion, imaging and response to treatment were recorded.

Results: Exocrine pancreatic function was normal in 20 patients with normal para-aminobenzoic acid and faecal elastase 1 levels. Eight patients had exocrine pancreatic insufficiency with low para-aminobenzoic acid and faecal elastase 1 levels, which improved with enzyme supplementation. In 14 of the 15 patients with low or borderline low para-aminobenzoic acid and normal faecal elastase 1 levels, a non-pancreatic cause was found; one patient had a false positive para-aminobenzoic acid test. Two had normal para-aminobenzoic acid but low faecal elastase 1 levels. One improved with pancreatic supplementation, and imaging revealed chronic pancreatitis. The other had a false positive faecal elastase 1 test related to profuse diarrhoea.

Conclusions: Faecal elastase 1 estimation is a simple, non-invasive, robust test of exocrine pancreatic insufficiency, performed on an out-patient stool sample. Its diagnostic performance is superior to that of the para-aminobenzoic acid test in investigating patients with diarrhoea or suspected steatorrhoea.

Publication types

  • Comparative Study

MeSH terms

  • 4-Aminobenzoic Acid / analysis*
  • Adult
  • Aged
  • Celiac Disease / etiology*
  • Diarrhea / etiology*
  • Exocrine Pancreatic Insufficiency / diagnosis*
  • Feces / enzymology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pancreatic Elastase / metabolism*
  • Prospective Studies


  • Pancreatic Elastase
  • 4-Aminobenzoic Acid