Which of the following statements about cholangitis are correct?

B. Associated biliary tract disease is always present.

C. Chills and fever are due to the presence of bacteria in the bile duct system.

D. The most common cause of cholangitis is choledocholithiasis.

DISCUSSION: Although Charcot's triad (pain, chills and fever, jaundice) is diagnostic of cholangitis, the complete triad occurs only in 50% to 70% of patients. Fever is the most common symptom; therefore, cholangitis should be considered in all patients who have unexplained fever. Episodes of pain, chills, and fever are often so brief as not to concern the patient. Cholangitis does not occur in the absence of partial or complete bile duct obstruction. All patients diagnosed as having cholangitis should have appropriate diagnostic studies to determine the cause. This usually involves cholangiography. The presence of bacteria in bile does not produce symptoms in the absence of partial or complete obstruction of the bile duct system. When obstruction is present, pressure within the system increases, giving rise to reflux of bacteria or their toxic products into the hepatic venous circulation. This cholangiovenous reflux produces chills, fever, and the hemodynamic changes of sepsis. Death may ensue if treatment is not instituted promptly. Choledocholithiasis, the most commonly associated problem, may produce partial or complete obstruction. When bacteria are not present in the bile duct system, choledocholithiasis may go undetected unless the degree of obstruction is sufficient to cause jaundice. Other causes of cholangitis are benign and malignant strictures, biliary-enteric anastomoses, invasive procedures, foreign bodies, and parasitic infestation of the bile ducts.