<prompt> 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 Murphys sign. A diagnosis of acute cholecystitis is made. What is the most likely finding?Serum bilirubin levels may be elevated.Cholelithiasis is present in 40-60.Bacteria are rarely found at operation.An elevated amylase level excludes this diagnosis.  <response>: 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. 