Hi Megan, sorry about the trouble you are having with your kitten. I would try her on some goat’s milk–you can get it in the milk section at the store. It has good probiotics in it and also will help settle her tummy. I think the best thing you are doing is getting her back to the vet. I presume she is using a litter box at this point, but you say she isn’t pooping. Is it possible that she is pooping somewhere else and you haven’t found out where? Sometimes cats (if they are having trouble going and it hurts) associate the litter box with their pain/discomfort and won’t go in the box. When you finally get things moving, you can place the poop in the box and she will figure out it’s okay. This is just a suggestion since I don’t know her specific problem. I hope they can get to the problem with your kitten, maybe give her an enema. Have they done an x-ray to see if there is a blockage: maybe she ate or chewed on something she shouldn’t have? These are questions to ask your vet. Keep us posted, good luck!