Fecal elastase measurement- beware; A cautionary tale

Fecal elastase testing of stool is increasingly utilized for the diagnosis of exocrine pancreatic insufficiency (EPI). However, testing is being used in other settings such as evaluation of diarrhea where interpretation may be inaccurate resulting in unwarranted additional testing and prescription of pancreatic enzymes.

Over a 24-month period, we prospectively evaluated all patients referred to a pancreas clinic for evaluation of EPI using the fecal elastase (FE-1) measurement. A thorough history was obtained to determine the nature and duration of the complaints, risk factors for pancreatic disease, stool characteristics as well as laboratory and imaging evaluation.

Over the study period, 54 patients (67 % female, median age 59 years (mean age 55 ± 16.5 years) were referred for "EPI" all of whom were evaluated for alteration in bowel habits. The median FE-1 concentration was 130 µg/g (range; 22 - >500 µg/g). Submitting a diarrheal stool for testing was prevalent. Established risk factors for pancreatic disease were present in 6. Because of the FE-1 results, additional cross-sectional abdominal imaging and/or endoscopic ultrasound were performed in 30 (56 %) and 15 (28 %) patients, respectively. The most common final diagnosis was irritable bowel syndrome (61 %); only 3 patients were considered to have chronic pancreatitis and true EPI.

Based upon our findings, most patients referred for EPI with an abnormal FE-1 measurement do not have malabsorption or EPI. Irritable bowel syndrome was the most common diagnosis. FE-1 testing is often misinterpreted, potentially overutilized and greater education is needed for its appropriate use and interpretation.