A Study of the Efficacy of ONS to Reduce Postoperative Complications Associated With Pancreatic Surgery

Patients undergoing pancreatic surgery for either chronic pancreatitis or known/suspected pancreatic cancer represent the study population for this clinical trial. Study subjects randomized to one of the ONS arms will be asked to consume the drink during the study intervention. Study visits immediately preoperative, and 1, 3, and 6 months following surgery will be in-person visits. If subjects are unable to return to our Institution for subsequent clinical care, these telephone interviews will be collected and acquisition of locally obtained laboratory tests will be attempted. Assessments performed during postoperative visits include: * Vital signs and physical examination * Blood samples * Performance status and strength * Quality of life measures * Postoperative complications and hospital readmissions (if any)