A 65-year-old woman is admitted with RUQ pain radiating to the right shoulder, accompanied by nausea and vomiting. Examination reveals tenderness in the RUQ and a positive Murphy's sign. A diagnosis of acute cholecystitis is made. What is the most likely finding?

Stones are found in the gallbladder in over 90% of patients with cholecystitis. Bacteria are cultured in bile in about half the patients undergoing surgery; however, many patients have previously received antibiotics. The gallbladder is usually distended in patients with acute cholecystitis but contracted in chronic cholecystitis.