Which parameter best reflects overall patency of bile flow?

• A. Bile salts
• B. Bilirubin
• C. Ammonia
• D. Lipids

Answer: (A)

Patency of bile flow is best assessed by a marker that directly follows bile’s journey from the liver to the gut. Bile salts are secreted into bile and rely on an unobstructed pathway to reach the intestine, where they are reabsorbed and recycled back to the liver. When bile flow is blocked, these bile salts can’t reach the intestine, their enterohepatic circulation is disrupted, and they accumulate in the bloodstream. That rise in serum bile salts occurs early and proportionally with cholestasis, making them a sensitive and direct indicator of biliary patency. Bilirubin can increase for multiple reasons, including hepatocellular injury, so it’s less specific for actual bile flow. Ammonia reflects liver detoxification capacity, not duct patency, and lipids don’t track biliary drainage well. Therefore, bile salts best reflect overall patency of bile flow.