Q. I need help! Poo isn't coming out of my kitten, what do I do? I can't contact a vet. They're closed
DESTINI R. HOLLOWAY, DVM
A. You can try a warm water saline enema from your local drug store. Use CAUTION not to get enema's that contain phosphate! These are toxic to pets and cats in particular. But a regular saline enema will do just fine. Then you can use K-Y jelly to gently insert the enema and hopefully help kitty to evacuate.
I would then follow up with the vet tomorrow on other things you can do to prevent this from occurring in the future (increasing water intake, adding fiber to the food if necessary, etc).