M.C.
My daughter had the same surgery at that age - i remember being just as worried about her being put under anesthsia - all of it. Please don't worry the doctors were wonderful - i was the one who went into the room as she went under and as the surgeon and I were walking down the hallway he said to me "oh by the way just as they go under they thrash about - don't let that scare you" so now i'm trying not to look scared for my little ones sake but she did indeed thrash about then out like a baby. they operated and she was fine. If you don't want to see that your husband should go in. I debated telling you that but i wish i had someone tell me that prior to just seconds before walking into the OR. Anyway - of course I have anohter story - i have a son too and he had a hernia operation as well - not on his umbilical cord but a regular hernia. He was 4 and he didn't thrash around - all the people in the OR sang "spongebob squarepants" theme song to him and before you know it he was ot without incident.
Your boy will be fine and by all means you should be there when he wakes up. He will need you. Decide with your husband who should go in with him but i am certain they will let you be there when he comes out of it.
good luck
M.