In 1901, Opie1 described acute hemorrhagic and necrotizing pancreatitis. He observed a stone impacted in the ampulla of Vater at autopsy in a case of acute hemorrhagic pancreatitis. The pancreatic duct was bile-stained. He demonstrated that, with pressure on the gall bladder, bile could be forced into the duct of Wirsung. He postulated the common-channel theory as a cause of the disease. His thesis was based upon observations made in 100 human bile- and pancreatic-duct dissections. He found that reflux from the bile duct into the pancreatic duct was possible in 30% of cases, when a stone obstructed the termination of the ducts.
Prior to Opie's report, Claude Bernard2 had demonstrated that bile and olive oil injected up the pancreatic ducts of experimental animals produced acute pancreatitis.
Later reports of Opie,3 in 1903, started a wave of experimental and clinical investigations into the possibility of bile reflux
DIFFENBAUGH WG, STROHL EL. Acute Hemorrhagic Pancreatitis Following Biliary-Tract Surgical Procedures. AMA Arch Surg. 1956;72(6):931–941. doi:10.1001/archsurg.1956.01270240043007