Kitten with bad diarrhea

I am really worried about my Siamese kitten, Keira. A couple months ago I started feeding my cats more canned food and switched to a higher quality dry food. Everyone did great, but eventually Keira started having very loose stools. Almost like diarrhea. She is 5 months by the way.

I talked to the vet and he said to try switching her to a strictly dry food diet before bringing her in. I switched her to Orijen and also got her dewormed. She has been doing a bit better but not fully improved.

This morning she was laying by her water dish in a puddle of watery diarrhea. I cleaned her up and put her in a large kennel with a litter box, paper towels, and I gave her a bowl of electrolyte mixture - she is drinking it on her own.

She won't eat which is super unusual as she has never missed a meal. I phoned the vet and am taking her tomorrow at 2.

In the meantime does anyone know what could be going on? She has always ate and drank well and had lots of energy. I am at a loss to know what else to do for her. Any insight would be appreciated!

With this being a kitten my first thought is a parasite that isn't cleared up with the routine dewormers.  You can get a fecal PCR test done to check for other parasites.  I also have a kitty that can't tolerate the high end grain free dry foods they will give her diarrhea.  My first thought with a kitten is a parasite.

I will have the vet check for parasites. Hopefully it is nothing too serious! Thank-you for your advice!