Procedure using a fine telescope / camera to inspect the inside of the:
Prostate in males
This is usually done to investigate causes of bleeding, infection, decrease bladder emptying / flow, overactive / underactive bladder symptoms.
It can be used for detecting cancer and obstruction.
This can be a day procedure and also can be done under sedation (but depends on what is specifically done)
Risk including urine bleeding and infection especially if a biopsy has been taken.
Other risks like making a hole in the bladder are rare.