Hi! My brother had this, my son and my nephew! With my son I waited till he was almost 1 year old because I couldn't bear to see an infant go in for surgery!!! However, my brother had it done when he was 3 years old and was old enough to remember unpleasant things from the surgery.
I think around 1 or 2 is perfect because they will be big enough physically to have a good reconstructive repair done, but they will also be young enough to NOT remember it...so they won't be self-conscious of it! :)
And as far as the pain...right after my son "came to" after surgery he was a little sore, but by the time we got home from the hospital and later that evening it was if nothing had ever happened to him! He never complained when I changed his diaper and he was running, climbing and bouncing all over without a single complaint!!! goodluck!