Answer:
Irrigate, meaning to supply with water.
This is typically done, if someone has undergone urological surgery.
The surgery can lead to bleeding in the bladder/urinary tracts and cause blocking.
As a result this causes pain and a feeling of pressure for the person.
To alleviate this, the medical team will insert a sterile urinary catheter (a small flexible tube through the urethra) and infuse sterile normal saline (usually warmed up) into the bladder. They will then clamp off the tube so the fluid stays in place, leave it for approximately 15-30 minutes.
Then return and un-clamp the bag/tube, allowing the fluid to drain, and hopefully clearing the bladder of the blood clots/foreign substances.