4.5 months old kitten has diarrhea that won't go away.

[Hypatiaa]

I found a 2-3 days old kitten without a mother and bottle fed her with kitten milk. She grew up well and adjusted do dry food around 1.5-2 months. I bought a medium tier cat food and there were no issues. After finishing the first package, I ordered a second package of the same food but the package was opened before. I thought about returning it but I had no time and place to buy another so I used it. Stool got kinda soft but not too much. Around same time she got her rabies vaccine, I told vet about diarrhea. They said it's probably because of food change and will go away in a couple days, and gave her the vaccine. So I gave her 4-5 days but still has diarrhea. I decided to buy dry food with better quality. Currently giving it by mixing it with old dry food. I also gave her wet kitten food because I thought she need to replace water and need more nutrition. But diarrhea is still there, stool has no shape and she is gassy. Not getting any better. Did I made things worse? Too much food chance or something else? She is joyful and playful as always, has no other issues and got parasite vaccines around 3 months old. I think it's because of too many food changes (old dry food with opened packaging, new dry food, different wet foods). She is very curious and trys to steal veggies from refrigerator, I don't let it happen as much as I can but she took one-two bites from lettuce. (didn't eat, just bite)
There are no other symptoms, appetite is good, grooms and cleans herself, playful, no vomiting etc

What do I do? Do I stop wet food complately? Do I keep giving good brand and medium brand together? Is it the vaccine? Is the situation too bad, do I need to go to vet? I need advice.

 

[sivyaleah]

Was a fecal exam done when you brought her for deworming? Is she currently on regular flea control?
There are parasites which require fecal testing to know what they are, for example coccidia and giarda.
I'd start by bringing her back in to the vet and request this if it has not been done yet. I'd be more suspicious for parasites than food changes at this age.

 

[Hypatiaa]

No fecal exam was performed but her deworming medicines should've worked against giardia too. (done around 1-1.5 months ago) She never had any fleas.

 

[Juniper_Junebug]

When my kitten had giardia (which presented as loose, stinky stools), it took two different meds to get rid of it and both were different than the dewormer she got for everything else. The first round of meds didn't take care of it, hence the second. I had fecal samples done several times, though it was nice that I could just drop off the sample and not have to bring her back to the vet every time.

 

[Hypatiaa]

My local vet can't perform fecal testing, I live in a small place. But I will still take her to get checked. If it won't get better, I will take her to other vets (kinda far). Thanks!