There isn't enough garlic in baby food to hurt the dogs. I have also never had a problem with baby food giving them the runs either but my dogs have stomachs of steel. I just looked at a jar of baby food and the only thing that was in it was chicken, water, and corn starch...nothing they wouldn't get on a regular basis anyhow. The corn starch may be an issue for your boy but whatever.
It seems that you have ruled every suggestion out but one more idea would be the evangers 100% meat. All it is is the meat and water. Other than that, I don't know.
There's no corn starch in the baby food I buy. It's chicken, water, and chicken broth. It's the beechnut chicken and chicken broth or turkey and turkey broth.
I have been told by more than one vet to make sure that there is no onion powder or garlic powder in the regular baby foods. I simply don't chance it since I've had quite a few tell me to stay away from it, when I can either make the same thing at home myself or buy the 100% meat that has nothing but broth, meat, and water in it, it's a little more expensive, but safer IMO. Again this is just my IMO.
It's hard not to rule out suggestions when I'm stuck with he can only have what he's already had plus he has allergies plus he has colitis. Not my fault the best puppy in the litter as a puppy turned out to be a host of medical issues. I do what I can with a nasty situation with him, and on top of it genius here ate his blanket and has an 8-10 inch incision down his stomach, plus one IN his stomach, plus 2 in his intestines so having a bout of diarrhea or vomiting can cause those to bust something that I sure don't want to deal with when I'm on a cruise ship and can't be gotten a hold of for 8 days, plus then 900 miles away the other 4 days, yes he has issues when he hasn't had major surgery with food restrictions. I don't mean to shoot down ideas, but I have to stick with what he has already eaten in the past that I know doesn't cause issues for him but because of his issues he rarely eats human food because I got fed up with the rash, the open sores, the itchies, the uncontrollable bloody diarrhea, so I have found a few things that work for him and just stick with those and call it good. Hopefully someone out there with an allergy and/or colitis dog can understand that predicament then add on top major surgery that he can literally bust his guts open if he gets diarrhea or vomiting and I 300% need to stick with what i know.
As I've said, someone's idea of the peanut butter, rice, green bean, kibble soaked in water paste and then freeze is GREAT, all things he's had, easy to come by, doesn't cause problems for him, quick to put together, won't break the bank, plus he likes everything and it's half way healthy (since he'll be getting this for 12-14 days).
Again thank you for the ideas, but I think we have it figured out now.
There's also Wellness 95% wahtever, chicken, Beef, etc that is meat and water also, I have a couple of cans, just in case you weren't aware of another brand.