A Double-blind Randomized Controled Prospective Clinical Trial of Somatostatin in the Prevention of post ERCP Pancreatitis

INTERVENTION: Group A:Somatostatin,6 mg, intravenously guttae once before ERCP;Group B:Somatostatin,6 mg, intravenously guttae once after ERCP ;Group C:physiological saline ; CONDITION: Post endoscopic retrograde cholangiopancreatography pancreatitis PRIMARY OUTCOME: serum concentration of amylaselipase;Serum lipas; SECONDARY OUTCOME: biochemical indices of liver and kidney function;Count of blood cell; INCLUSION CRITERIA: 1.Male and female aged 18 to 80 years old; 2.Able and willing to perform ERCP in our hospital during Dec.2008 to Dec.2009; 3.The serum‐amylase and serum‐lipase is normal before ERCP.