1.   A lint catcher like that can block the duct, and could cause a fire.

2.   If the infection reaches the testicles, it can produce scar tissue that blocks sperm ducts, causing sterility.

3.   It was blocking the duct.

4.   When the ducts get blocked, bile backs up and migrates elsewhere, to the skin and eyes, causing itching and the yellowing known as jaundice.

5.   However the Ministry of Defence denied the group managed to block the duct.