['To evaluate whether the extended secretin-stimulated direct endoscopic pancreatic function test (ePFT) technique is superior to the rapid 15 minute secretin-stimulated ePFT in determining pancreatic exocrine function.', 'We conducted a retrospective study of 53 patients with chronic abdominal pain and normal pancreatic imaging. These patients had ePFT testing with the following modified endoscopic collection system. Porcine synthetic or human secretin was intravenously administered 15 minutes before endoscopic duodenal aspiration. The first 10-minute collection was performed in the third portion of the duodenum. A Liguory drainage tube was placed in the third portion of the duodenum. Two additional 10-minute-period collections were obtained via the drainage tube at 30 and 45 minutes after intravenous administration of secretin. All fluid collections were analyzed for bicarbonate (HCO3) concentration.', 'Peak HCO3 concentrations at 15 minutes occurred in 62%, at 30 to 40 minutes in 23%, and at 45 to 55 minutes in 15%. Normal concentrations of HCO3 (> or =80 mEq/L) were seen in 70%, abnormal concentration in 7%, and equivocal concentrations (60-79 mEq/L) in 23% even after 55 minutes of duodenal collections.'] Is pancreatic function testing best determined by the extended endoscopic collection technique?