This study was undertaken to determine whether routine use of a modified triple-lumen five French sphincter of Oddi manometry catheter would reduce the frequency and severity of post-manometry pancreatitis and pancreatic enzyme elevation. Seventy-six patients were alternately assigned to undergo sphincter of Oddi manometry (SOM) with a standard perfusion (infused group) catheter or the newly developed aspiration (aspirated group) catheter. After SOM, there were significantly more patients in the infused group with both amylase and lipase values elevated at least two times the upper limits of normal at 2 (p less than 0.001), 6 (p = 0.01), and 18 hours (p = 0.03) after the procedure. As compared with the standard perfusion system, the aspiration catheter was associated with a decreased frequency of clinical pancreatitis (23.5% vs. 3%, p = 0.01) reduced hospital stay (5 +/- 1.83 days, mean +/- SE, versus 1 day; p = 0.03) and milder pancreatitis. The aspiration manometry catheter should be considered for standard use for SOM, particularly if the pancreatic duct sphincter is being evaluated.