Utility of fecal fat concentrations as screening test in pancreatic insufficiency.

We explored the utility of fecal fat concentration (gram fecal fat per 100 gram wet stool weight) as a screening test for pancreatic steatorrhea. Data were analyzed on 24 patients with pancreatic insufficiency and steatorrhea, six groups of patients (N = 70) with nonpancreatic causes of steatorrhea, and 31 controls without steatorrhea. Patients with pancreatic steatorrhea had significantly (P less than 0.05) higher mean fecal fat concentrations than all groups except for patients with hepatobiliary disease. Using a fecal fat concentration of greater than 9.5% as a cutoff point in all patients with steatorrhea, the test was 41.7% sensitive and 92.0% specific for the diagnosis of pancreatic insufficiency. For patients with fecal fat excretion greater than 20 g/day, the test increased in sensitivity to 61.5% but specificity dropped to 85.3%. Measurements of fecal fat concentrations are therefore only moderately helpful, and further evidence is required to secure a diagnosis of pancreatic steatorrhea.