Final answer:
The causes of priapism are all the following except severe scrotal pain.
Step-by-step explanation:
The causes of priapism are all the following except severe scrotal pain. Priapism is a prolonged and painful erection that occurs without sexual stimulation. It can be caused by various factors such as spinal cord injuries, leukemia, and sickle cell disease. Severe scrotal pain, on the other hand, is not a known cause of priapism.