A 60 y.o. woman complains of unbearable pains in the right hypochondrium. In the medical hystory: acute pancreatitis. Body temperature is 38,2°C. Objectively: sclera icteritiousness. No symptoms of peritonium irritation are present. There are positive Ortner's and Hubergrits-Skulski's symptoms. Urine diastase is 320 g/h. What diagnosis is the most probable?