"It felt strange, and I asked why," he told the news outlet. "They said: 'Just do what we tell you'."
With Wang on the table the doctors applied anaesthetic and proceeded to remove his haemorrhoids.
"I really never knew I had haemorrhoids," the 29-year-old said.
"When I was on the operating table I heard a baby crying and I was very happy, and I wanted to hold it.
"But I couldn't move because I started to feel pain."
It is unclear if the unsuspecting patient had a general or local anaesthetic.
Wang confirmed that his wife gave birth to a healthy baby via Caesarian section.
The hospital reportedly offered the man 5000 yuan ($1046) compensation for the mix up although negotiations between both parties are still on going.