Don't worry!! My son 1 year 10 months did this operation in private Hosiptal. The operation only took 15 - 30mins. He woke up already when he left the Operation room. However, my doctor requested us to stay in hosiptal one night for observation.
The most difficult time for my son is he was not allowed to eat anything after the operation. We need to wait for 3 hours to feed him. He was so hungry. After eating, he can sing and talk as normal. The second day, everything back to normal. He seemed not painful at all.