A 55-year-old male presents with severe, constant pain in the upper abdomen and back. He also reports nausea, vomiting, and fever. Blood tests show elevated white blood cell count and amylase/lipase levels. What is the likely diagnosis, and what are the next steps?
This patient's symptoms and elevated amylase and lipase levels are suggestive of acute pancreatitis, which can be caused by gallstones blocking the pancreatic duct. The next steps would be to order an abdominal ultrasound or CT scan to visualize the gallbladder and pancreas and confirm the presence of gallstones. The patient will require hospital admission for pain management, fluid resuscitation, and possibly gallbladder surgery once the pancreatitis has resolved.