How old is he?? Did you get a temp on him??? The color of the poop helps to tell what is going on as well. First thing I would do is give him a cd antitoxin shot. When you say it smells bad I think salmonella, it is kinda a grey color???? I understand the finance thing so to be honest what i do with a kid that Im unsure of with scours is treat for what all I think it could be. If he is older then a few weeks then I would rule out e coli, salmonilla I use neomycin, also a shot of la200, last year was told pen. works well so I used that. Coccidiosis causes scours and there is a long list of meds you can use for that, look up coccidiosis, I use albon. But no matter what you want to give that antitoxin, you can also give the pepto, I have mixed feelings on that. Pepto can be great to ease the tummy but if its something bad in there its best if you let the animal get it out, which is what the runs do is try and get all of that crap out. Also keeping him hydrated is #1, that will kill faster then anything he might have. Hope this helps you out