What could be wrong with my cats?

Okay so i had my one cat for a year then we got a kitten. Now they are both having diarreah really badly . And watery. Nothing else is wrong, he is playfull, eating and drinking everything. Just the crapping. I cant get them to the vet right now because i dont have a job (Im 17 and i put resumes out but noone has called) I had some money saved up but i used it to get my at neutered and my dog her shots. Anyone have any ideas on what cause really bad diarreah without any other symptoms?Sorry i guess i should have added that no the kitten is not UTD on shots.. and this really bad diarreah has been going on for like... a month. Thats why im so confused, because they are not dehydrated or anything, my older cats is only 14 months old and the kitten is 6 months. Nothing was wrong with my cat before the kitten came.. so the kitten brought it in. We got the kitten from a farm. We also have 2 older cats and nothing is wrong with them. Ugh soo confused on what could be wrong!

Keep your cat comfortable, with access to a clean litter box and fresh water. If his diarrhea is mild, or you know he's eaten something that prompted it (including "people food"), you can offer him a bland diet, such as white rice with plain boiled chicken or boiled hamburger meat (no salt or pepper on his food, please). This is easily digestible and should calm his system. You can also mix some fiber granules, such as Metamucil, in his food, to add bulk to his stool. Or try a spoonful of plain yogurt . Monitor his activity to see if he visits the litter box less frequently, and note if the consistency of the stool returns to its usual form.

It could just be them getting used to eachother. Is your new kitten UTD on shots like your other cat?

Could be poisoned? Could have some kind of cat disease ? maybe what you feed them? Look on the internet and find out.

It's impossible to say what's caused it without the vet doing tests. One thing you could try is plain boiled rice and chicken. Make sure you offer plenty of clean water - not milk, which can aggravate an upset stomach, and clean up well after them so as not to spread any infection around. Make sure you wear gloves and wash your hands really thoroughly. If there's no improvement in 24 hours then, while I appreciate your financial situation, you really do need to get some professional help because a small kitten could die from dehydration in quite a short time.Do you have a Blue Cross or animal shelter nearby that will treat animals for free or for a small donation?

Just don't be feeding your cats ANY dairy like milk or cheese or yogurt. After kitten grows into a young cat, which he has- he cannot be drinking milk and dairy or they will get diarrhea.