tummy ache

Hi
I came home after a long day at school today to find cat vomit on my livingroom and bedroom floor. Of course there was no way of knowing who did it, so I fed them their wet and called dad. The answer came rather quickly...Chester was fine when I left, but seems to have been vomitting semi-regularly since after 2pm today.
NOW
I keep strings and the such to as much as a limit as I can (pick them up and put them away when I see them). He also has never been interested in them. There has been no change in bathrooming or eating habbits at all (except for after I got home, when he only ate half his dinner). He seems uncomfortable, but as if his stomach hurts (guarding it). I DO have quite a few dirty dishes from a couple of days up on the counter. My hypothesis is that he got into them while I was away and ate something that had gone sour. My good friend, who is a herbalist said that she had had some luck with putting camomille tea in tuna juice (to hide the smell) in the past, and looked up peppermint for me, cuz that's what I have for MY stomach. He had some of the mixture to drink, but seems uncomfortable still. Mind you, this was about 5 minutes ago.
If this gets worse, or if he's still the same in the moring, we're going to the vet
I'm looking for nursing care stuff to help with this tummy ache.

Thanks
Jess

Update: 5 mins later.
I did a head to tail check. His anus is not extended (always was a sign of constipation), his hydration is good (back of the neck falling back in place quickly), but his stomach is sore, and he seems to be a bit more "caved in" around his lower stomach area (near his hind legs) than usual. It's hard to check him more thoroughly, he's cowering quite a bit.
Jess

Are you able to isolate him so he has his own litterbox...so you can monitor any 'progress' ?

Not really, because if I do he stands near the door and howels because he's lonely. I don't want to stress him more. Right now he's laying on the couch with me, and is still bright eyed...seems a little bit less uncomfortable since the last vomitting (mind you he hasn't eaten or had anything to drink since then). I WILL follow him around all evening to moniter him, and if need be we can lock him in the bedroom with me, but then Dynah is left out for the night.

Just wondering how Chester is doing today? Lots of get well wishes for him.

aww, thanks Paula. A few hours after I got the tea/tuna juice into him he started acting more allert, and eventually started playing with Dynah. This morning he kept his breakfast down, and seems normal again. I'm so happy he's feeling better, he really did throw up a whole lot last night (I guess sometimes we all need to just get it out). I will confirm his okness when I get home from school and empty the littler boxes...so far no vomit today though, and its 1pm already!