New kitten with extremely stinky poo

I came across this forum doing a search on why our new Kitten's poo stink so so so badly, I have another kitten same age, her's doesn't stink it did when I first got her a month ago but I think that was more the generic store brand cat litter and not so much her, Now I have been using Fresh Step litter for a month(i quickly used up the generic brand) On Thursday the 25th we got a new kitten (From Craigslist) the lady said he'd been wormed, and I haven't seen any Both are going to the Vet next month for shots and I'll bring up this stinky poo with him then, But When I saw this

"[color= rgb(24, 24, 24)]Definatly have any REALLY stinky poo checked by a vet for coccidia,giardia or worms. Gas and smelly poop is a sure bet for any of these things."[/color]

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[font=arial, helvetica, sans-serif]After Reading that I started Freaking out, I raise Parrots so I'm familiar with both coccidia and giardia (not that mine have had it but I've researched it very well for birds) and I know they can be spread between animals and humans, So here I sit with 2 kittens, a Dog 60 plus birds and 4 people (2 are children) in my house and I'm freaking out thinking my new kitten is going to give us some disease [/font]

[font=arial, helvetica, sans-serif]I guess I'm looking for some reassurance that not all nasty stinky poo is caused by these diseases. and some suggestions of what it could be [/font]

[font=arial, helvetica, sans-serif]I don't know what food he ate before I got him but since I got him he's been eating the same food as my other kitten which is kit and kaboodle dry cat food and he'll be sharing a can of 9lives Canned moist food today, I give it once a week to my other kitten [/font]

[font=arial, helvetica, sans-serif]He is a Bengal Kitten that I was told was 3-4 months old, My other Kitten is a Manx and she's 3 1/2 months old. [/font]

[font=arial, helvetica, sans-serif]I don't think I have to worry about my dog getting anything since she doesn't get in the litter box and it has a lid on it with a  door so even if she was interested she'd be scared of it (she is scared of things like that lol) [/font]

[font=arial, helvetica, sans-serif]Thank you in advance for any help and reassurance you can give until I get to the vets in a couple days  [/font]

When I first got my kittens they had VERY stinky ones too. I got them wormed and that was the end of it. Try not to worry too much, it could just be worms and easily treated. I never saw any worms either but that was the cause (round worms). I noticed that certain foods cause stronger litter box odors too. Just a thought. I love Bengals ! Can you share some pictures ?

Thank you I've had others tell me it could also be stress, different food than he's used to. Hopefully that is all it is, she said she gave him worm medicine, but did not say how long ago, she gave it to him. 

I Made a post in the New Members area with pictures  

I had to do the worm meds twice, spaced out a few weeks I think. Maybe she just gave your cat the first dose. Anyway, I'm off to see your pictures.