New kitten vomiting and pooping blood

Kobe, 8 weeks old

Hello,

While googling this very subject I stumbled upon this site and thought that, maybe if I was more specific about my situation than some of the questions/threads I came across, I could get a more concise answer- so I made an account.
For the record I phoned the vet this morning and will be likely taking my baby in tonight, especially if I don't hear any positive responses (maybe from people who have been in the same boat as me.)

I adopted two 8-week old male kittens Saturday night from an ad on Kijiji.com. The woman told me that they were dewormed and de-flead but not yet vaccinated and of course, not yet neutered. 

The night I got them home they were both energetic and playful- however a few hours after they had gotten situated, one of the boys heaved a couple times and threw up on the rug. The vomit was liquidy and brown- the color of cat crunchies. I mopped it up and placed him in the litter box in case he had some more in him. He sat there for a moment and then pooped. His poop seemed fine, maybe a little soft but not alarming. (however on his way out of the litterbox he stepped in his poop and tracked it back onto the carpet- I was unsure if this was odd behavior as I've had cats all my life (not kittens this young mind you) and I know that they tend to be extremely clean and careful of stuff like that. I wondered if this meant that he was ill and disoriented, or maybe kittens this small are just generally clumsy and unaware?) Anyways right after this he went back to playing.

That night he curled up with his brother in a pile of blankets beside my bed and they both slept through the whole night- no more accidents or messes. 

Sunday the kittens were both acting normally, playing really hard for a few hours then napping, on and off the whole day. They drank and ate normally (wellness kitten formula crunchies- I'm assuming this is not what they were being fed at their old house btw.) They also groomed normally which I was happy to see after the poop-stepping incident. 
When night time came, the same little guy had a liquidy poop in the box and stepped in it again. I wiped him up and put them to bed.

Early in the morning, he threw up another liquid brown puddle. This was twice now, and honestly I wouldn't be concerned if it wasn't for what happened next: Knowing full well where the box was, and having used it several times now, he had a big liquid poop right on my couch.   When I went to mop it up, it had a fair bit of blood in it. 

Again, right after this he went right back to playing, and as of right now, he's napping with his brother.

Here's what confuses me: 

-He has hardly left his brother's side the entire weekend and yet, he is the only one showing sickly symptoms. 
-His bro is seemingly healthy and they literally eat, drink, sleep, groom, and play the exact same amounts.

-If it wasn't for the blood I would chalk up the small barfs to a change in diet and perhaps a more sensitive stomach than his sibling?

In summary:

Several normal poops, one runny one, and one bloody runny one- and 2 vomits over the course of the weekend.

Anyone experienced similar problems?

I would for sure take them both to the vet. It is a really good idea to get a check up right when you get a new kitten. It sounds like the sick one probably has a parasite and they will both have to be treated. They should also get vaccinated soon (but not while sick). 

I just got a new kitten too. She was a little unsure about the littler box the first day, and didn't defecate until the following night and had a tiny bit of blood on her fur. I just took her to the vet (was going to anyway to make sure she was healthy) and they told me that she probably was constipated which caused the blood. They ran the fecal sample that I brought in just to be safe, so bring a sample with you so you don't have to make another trip. 

Thanks. I made an appointment for 4:30pm today.
I didn't plan to take them in so soon after getting them only because my bank account is a little tapped after having paid the adoption fee and all supplies- but I can make it happen. I was going to take them in for vaccinations sometime next week, however as you said if they are legitimately sick I won't be able to. 
Wish me luck! In case anyone is having a similar issue, I'll make a post after he sees the vet tonight.

to TCS!

Good luck! Taking a fecal sample is a really good idea, because otherwise you'll probably find yourself taking one in tomorrow at the vet's request. Parasites in young kittens are common, though it could also be as simple as the food change or stress from moving into a new home. Let us know how it goes.

Kittens can be a bit clumsy, so it's not surprising that he stepped in his feces.

I don't have any advice for you except to suggest that you should try to find out what the kittens were being fed in their former home and stick to that same food at least for now.  Changing foods too quickly is hard on any cat's system.

I'm sending you lots of good luck vibes and hoping your vet can easily fix what is wrong with your new kitten.  And BTW, he is absolutely adorable!!

Hey guys, FYI we took both boys into the vet last night:

She says she assumes that he is infected with a parasite.

He was dehydrated and his stomach was a bit hard.

She gave both boys one half of a dewormer pill each for good measure, and prescribed an antibiotic that works on both parasites and an inflamed/upset stomach. (metronidazole) She also sold us a few cans of a safe, bland food that would lessen the severity of nausea/runs/sore tummy. (royal canin kitten formula)

She injected some saline under his skin to help hydrate him, and recommended we add water to the canned food to help keep him hydrated.

He slept well last night (on the bed with me) and played with his bro lots this morning. At the moment he's a little standoffish (he loves to hide in corners and he's not letting me pet him very much) but I get it. I'm the bad guy for forcing him to take his medicine   lol here's hoping he forgives me when he's better. 

Hope this helps anyone who's in a similar situation xx

that he's over this really quickly!