Inclusion Criteria:  Adult patients ≥ 18 years of age with definite CP undergoing decompressive invasive treatments (endoscopic therapy or surgery) to relieve main pancreatic duct obstruction due to stones and/or stricture for management of pain.  Endoscopic therapy: Endoscopic Retrograde Cholangiopancreatography (ERCP) with pancreatic duct stone removal, stent placement, and/or stricture dilation, ± intraductal lithotripsy or Extracorporeal Shock Wave Lithotripsy (ESWL). Surgery: drainage procedures (Frey and Puestow operations)  Exclusion Criteria:  Patients with chronic pain from conditions other than CP Patients < 18 years of age Patients who have had endoscopic therapy within the past 12 months Patients who have undergone prior pancreatic surgery Patients who have resective surgical procedure planned (eg. Whipple procedure, Total Pancreatectomy) Patients with peripheral sensory deficits  Patients with known pregnancy at the time of study screening**  Note: Women who become pregnant during the course of the study can no longer participate in P-QST testing.