The first 48 hours after Cai's neuter were rough. He spent lots of time just lying in his crate whining and crying, and refused water - I had to squirt it into his mouth with a syringe. When he finally peed, it was on my bed. When he finally pooped, it turned into almost 12 hours of diarrhea (and I couldn't wash his butt fluff properly due to the stitches).
After that, though, things improved immensely. On Monday Cai was no longer whining, would wag his tail happily when I greeted him, drank occasionally when I brought him a bowl of fresh water, and ate all of breakfast and dinner -- and has continued eating every meal since. (It's actually unusual for his appetite to stay strong for 4 days in a row, so I'm quite pleased.) He's still sleeping a lot, but also spent time chewing on a bully stick and sitting on my lap.
His stitches look fine and will come out on Saturday morning - just in time for the hand off to Sherry on Sunday, since I'll be in Hawaii next week. Good luck, Sherry!