Faecal elastase 1 is a pancreatic enzyme that is excreted in the faeces and can be used as a marker of pancreatic function. Low levels of faecal elastase 1 can indicate pancreatic insufficiency, which can lead to malabsorption and other gastrointestinal symptoms. However watery stools can lead to falsely low levels of faecal elastase. The sensitivity of faecal elastase-1 for identifying exocrine pancreatic disease has been shown to be approximately 75%, with improving accuracy when watery samples are excluded.
References:
Jones, A.M., 2023. The clinical and laboratory impact of reporting faecal elastase-1 in watery stool samples. Annals of Clinical Biochemistry, 60(1), pp.72-74.
Brydon WG, Kingstone K, Ghosh S. Limitations of faecal elastase-1 and chymotrypsin as tests of exocrine pancreatic disease in adults. Ann Clin Biochem. 2004 Jan;41(Pt 1):78-81