A 55-year-old man comes to the office complaining of pain in the epigastric and left upper abdominal pain that radiates to the back. These symptoms started about three days ago. Anorexia, nausea, vomiting, and flatulence are also reported. The patient says that his stool has been fatty, frothy, and foul-smelling. Blood chemistry shows increased amylase, lipase, AST, and lipid levels. Calcium and potassium are both low. Based on these findings, the patient is diagnosed with: