The causes of death in the first two weeks after the onset of pancreatitis are mostly systemic inflammatory response syndrome (SIRS) and multiorgan failure (MODS), while in the later stages death is mainly due to complications of necrotizing pancreatitis. The pathophysiological process and the pathogenesis of treatment of biliary pancreatitis remain unknown. Some studies suggest that stones may compress the tissue between the distal bile duct and the pancreatic duct, leading to pancreatic duct obstruction, or cause obstruction of the common channel (Vater’s vena cava), allowing bile to flow back into the pancreatic duct. Both of these mechanisms may lead to increased pancreatic duct pressure. Obstruction of the pancreatic duct will lead to reflux of bile and pancreatic juice, high pancreatic duct pressure and abnormal secretion of alveolar cells, which will further lead to ductal damage, release of pancreatic enzymes into the interstitial matrix of the gland, and pancreatic self-digestion, thus triggering pancreatitis. Not all patients with chronic pancreatitis with pancreatic duct obstruction will have an acute attack; therefore, acute “obstruction” may be an important factor in the development of acute pancreatitis. Excluding irritation, more than 50% of acute pancreatitis is associated with the discharge of small stones ≤5 mm in diameter from the bile duct. 85% to 95% of patients with acute pancreatitis have stones found in the stool, which is 10% of patients with active gallstones (not associated with pancreatitis). Analysis of surgical cases in patients with pancreatitis in the 1980s showed that 63% of patients who underwent surgery within 48 hours of admission had bile duct stones and 78% had jugular stones. It has been proposed that early sphincterotomy (EST) via ERCP to remove obstructing stones could help improve the course of pancreatitis. In fact, bile drainage is essential for some patients. However, the value of ERCP in pancreatitis varies according to the results of different clinical studies, so the question for the endoscopist is how to select those patients who can benefit from ERCP and EST.