Final answer:
In cystic fibrosis, blockage of the pancreatic duct by thick mucus prevents the flow of pancreatic juice into the duodenum, causing a backup of pancreatic juice into the liver.
Step-by-step explanation:
In cystic fibrosis, blockage of the pancreatic duct by thick mucus prevents the flow of pancreatic juice into the duodenum, leading to a backup of pancreatic juice into the liver via the bile duct.