Patients underwent first-time ERCP were randomly assigned (1:1) to receive either LRS at a rate of 150 ml/hr starting 2 hours prior to procedure, and continued during and after procedure to complete 24 hours (aggressive hydration) or LRS at a rate calculated by the Holliday-Segar method given peri-procedurally as described earlier (standard hydration). Visual analog scale, serum amylase, lipase, C-reactive protein (CRP), and urine analysis were assessed prior to procedure and 24 hours after. The primary endpoint was post ERCP pancreatitis defined as new or increased epigastric pain persisting for ≥24 hours, elevation of amylase or lipase >3 times the upper limit of normal.