Cystic fibrosis blocks the flow of which digestive juice?

• A. Blocked flow of bile
• B. Overproduction of pancreatic juice
• C. Inflammation of pancreas
• D. Blocked flow of pancreatic juice

Answer: (D)

In cystic fibrosis, thick mucus clogging exocrine ducts blocks the pancreatic duct, preventing pancreatic juice from reaching the small intestine. This juice contains the enzymes—lipase for fats, amylase for carbohydrates, and proteases for proteins—that are essential for digestion. When its flow is blocked, digestion is incomplete, leading to malabsorption and symptoms like fatty stools. It’s not about an overproduction of pancreatic juice, and while inflammation of the pancreas can occur, the defining effect described is the blocked flow of pancreatic enzymes.