Indometacin With or Without Aggressive Intravenous Hydration to Prevent Pancreatitis After Pancreatic Extracorporeal Shock Wave Lithotripsy

Inclusion Criteria: * Patients with painful chronic pancreatitis eligible for P-ESWL treatment * Ages between 18-85 years * Providing informed consent Exclusion Criteria: * Patients readmitted to the hospital for ESWL during the study period * contraindications to ESWL * Signs of congestive heart failure, such as pitting edema or a New York Heart Association classification greater than class I heart failure. For patients ≥ 70 years old, brain natriuretic peptide (BNP) and cardiac ultrasound would be performed before ESWL. Patients with BNP\>100pg/ml or Ejection Fraction value\<50% should be excluded * Respiratory insufficiency (pO2 \< 60 mmHg or saturation \< 90% despite FiO2 of 30% or requiring mechanical ventilation). For patients ≥ 70 years old, pulmonary function tests would be performed before ESWL. Patients with Forced Expiratory Volume in the first second (FEV1) \<70% are excluded * Patients receiving more than 1.5 mL/kg/h or 3 L/24 h of intravenous fluids in the 24 h before ESWL * Hypotension (systolic blood pressure \<90 mmHg or mean arterial pressure \<70 mmHg) * Hypo- or hypernatremia (serum Na+ levels \< 130 or \> 150 mmol/L) * Severe liver disease (cirrhosis with ascites, liver abscess) * receiving NSAIDs within 7 days * Contraindications for rectal use of NSAIDs (renal dysfunction with serum creatinine \>120 μmol/L, allergy, active gastrointestinal bleeding, ulcer disease, and NSAID use for other indications \[other than cardioprotective aspirin\]) * presence of coagulopathy or received anticoagulation therapy within 3 days * acute pancreatitis within 3 days * known active cardiovascular or cerebrovascular disease * pregnant or breastfeeding women * without a rectum (ie, status post-total proctocolectomy)