2 Cats Not eating

Hello, I have 2 3 month old cat brothers, both stopped eating on Thursday, one of them was vomiting but still energetic and playful, yesterday I decided to take them to the vet because they were still not eating, the vet checked for fever, their stomach and he told me they were ok, no fever but one of them had tiny hairballs probably and also he gave them an anti parasites pill and said that should be enough and they should start eating soon, and to add a little bit of olive oil to their food to help with hairballs, well it's been 24 hours and they are still no eating and one of them vomited the little tuna he previously water and pooped some diarrhea, should I be worried or i need to wait a little bit longer for them to start eating properly?

So the kittens weren't eating, you took them to the vets, the vet didn't find anything and said to watch and wait - you have watched and waited, and 24 hours later the kittens are still not eating, one has vomited again and diarrhoea is present.   A great line at the end of consultations is, 'So if this doesn't improve, at what point do you want to see me again?' - we try to let you know, but it can sometimes be missed, so this is good to keep in mind.  Meanwhile, it sounds as though you still need to ask how soon your kitten needs to be seen - this can be worked out in a phone call, known as 'Triage' and can be done by your emergency vet if you feel that it may be an emergency.  Emergency vets will cover issues such as, how likely the kitten is to be dehydrated (and therefore need emergency fluids) or whether this will wait until tomorrow.  I hope that that helps.

Thanks for the replay, yeah the vet wasn't very clear, he just said I should come back around October 8 to vaccinate them, I gave them a little bit of water with a syringe for now but they're playful and energetic as if nothing was wrong but they both are still not eating anything.and they do look skinnier than before so I'm worried, vet is closed on Sunday but if they still haven't improved by tomorrow I will take them to the vet again and see what happens, hopefully they can recover because im really stressed, I tried sardines, chicken, different patte foods, tuna and nope, they are not even interested, no vomit though I think so that's good I guess