Thank you so, so much for all the vibes.
He's through the 2 hours since the end of the op (nearly 3) and is "as well as can be expected". He was sitting up and aware of his surroundings and NHB said he was "happy with him", felt his chances of surviving were good now he'd got that far. He's at FHB's home, so I get to ring for update at 7.45, before the phones go over.
It's occurred to me that poor Elijah, who was starved and neglected in his early life (he was thin when he came to live with me at about 8 months old) probably
got in the habit of eating his hard droppings then as he had nothing else to eat