Mrs. Catbug,
I’m sorry your little guy passed away. Not every kit is for our world.
You need to get you other kit to the vet because he needs a enema. Once he’s had a BM, I recommend you start with Goats milk. Some vets. don’t know about Goats’ milk but here in TDKland, we recommend Goats’ milk for kittens. Cats are lactose intolerant and can’t digest cows milk. Goats’ milk is full of nutrients, probiotics and gentler on their tummies. This can also regulate the poop. You can find it in the dairy section or the concentrate in the baking aisle. Mix the concentrate 1:1 with water or pedylite. If, at any time, they seem lethargic put a dab of Karo syrup or honey in their mouth. Also, a smidgen of mineral oil in their formula can usually help them poop. You can put a dab of Neosporin on his bum if he gets sore. He needs to poop but he doesn’t know how to do it on his own.
You’re not doing anything wrong. Some kits don’t have productive BMs and once that starts they usually need a enema to help them. DO NOT DO THIS YOURSELF!
Good Luck and keep in touch,
PG