Complications of severe pancreatitis primarily include: 1. Acute peripancreatic fluid collection and interstitial edematous pancreatitis, where fluid accumulates around the pancreas without necrosis. This can be diagnosed with enhanced CT. 2. Pancreatic pseudocysts, characterized by fluid encapsulated by a clearly defined inflammatory cyst wall around the pancreas, with no or minimal necrosis, commonly occurring around four weeks after an episode of interstitial edematous pancreatitis. 3. Accumulation of acute necrotic material, involving necrotic tissue and liquids from necrotizing pancreatitis, including the parenchyma and peripancreatic tissues, also diagnosable through enhanced CT. 4. Encapsulated necrosis, observable as a clearly defined inflammatory encapsulation of the pancreas and peripancreatic tissues, commonly occurring four weeks post an episode of necrotizing pancreatitis.