A 44 year old overweight woman was admitted with two days of persistent right upper quadrant pain and nausea. Examination demonstrated right upper quadrant tenderness, positive Murphy’s sign, normal bowel sounds and no abdominal guarding. Ultrasound revealed a thickened gallbladder wall and a gallstone in the cystic duct. She was admitted for observation, intravenous fluids and analgesia. Two days later her pain worsens and she develops a fever and jaundice. Examination demonstrates increased tenderness but no other new signs. Bloods investigation reveals a leukocytosis, hyperbilirubinemia, elevated alkaline phosphatase with normal transaminase. What is the most likely diagnosis?
A Acute cholangitis
B Acute cholecystitis
C Acute pancreatitis
D Biliary colic
E Intestinal perforation