I have not heard back from you but want to leave my thoughts for your return (since you appear offline now).
Now in regards ***** ***** question, these could cause a gut blockage if he has eaten quite a bit. Though this could cause pancreatitis and severe gut irritation as well which would appear the same way.
With this all in mind, as long as he can keep water down, we can try some home supportive care to try to settle his stomach. To start, if he hasn’t just vomited (since otherwise we’d need to rest the stomach for a few hours first), you can consider treating with an OTC pet safe antacid [ie Pepcid (More Info/Dose @http://www.petplace.com/article/drug-library/library/over-the-counter/famotidine-pepcid), Zantac (More Info/Dose @ http://www.petplace.com/article/drug-library/library/over-the-counter/ranitidine-hcl-zantac)]. Whichever you choose, we’d give this 20 minutes before offering food to allow absorption. Of course, do double check with your vet if he has a known health issues or is on any medications you haven't mentioned. Also if you give this and he cannot keep it down due to nausea that is usually a red flag that we need to bypass his mouth with injectable anti-vomiting medication from his vet.
Once he is more settled, you can plan to try small meals of a light/easily digestible diet. Examples you can use are cooked white rice with boiled chicken, boiled white fish, or scrambled eggs, or meat baby food (garlic/onion free only) that can be used too. The aim of these diets is that they will be better tolerated/absorbed by the compromised gut. Therefore, it should get more nutrients in and result in less GI upset and less diarrhea. Fiber (ie canned pumpkin, all bran) should also be added to these meals to help push the corn material through the gut and firm the stools. You can also add an OTC probiotic (ie Benebac, Fortiflora) to this to normalize the gut’s good bacteria in the wake of this ingestion. As long as improvement is being seen, I usually advise continuing this until the signs are settled, and then weaning slowly back to what you normally feed.
Since dehydration is a risk with what he as eaten, we need to keep an eye on his hydration. To check this and make sure dehydration isn’t an issue, there are a few parameters you can test. Further to checking for gum moisture, you will want to make sure his eyes are not looking sunken and that he doesn’t have a "skin tent" when you lift the skin. To see how to check these, you can find a good video HERE (http://www.ehow.com/video_12232503_dog-dehydrated.html). If you do see any of these signs already, then that would be our cue to have him seen before this becomes an additional issue (especially since its often dehydration that makes them feel unwell).
Overall, his ingestion of feed corn kernels does carry some risk of blockage but also the above. And all of these could trigger vomiting and diarrhea as you are seeing. Of course, if he has pale gums, belly pain or there is blood in either vomit or diarrhea; we'd want him seen now. Otherwise, you can try supportive care to try to settle his stomach. Though if he cannot keep that or water down, appears dehydrated already, or doesn’t respond to the above within 12-24 hours; then we'd want to get his vet involved. They can assess his hydration, determine if we have a blockage that needs to be addressed, and if that can be ruled out, then get him onto injectable anti-vomiting medication +/- fluids to settle his gut.
Please take care,
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