Belle sounds like quite a challenge with everything she has been eating. Now hopefully there are no burns or damage to her mouth from those cords and hopefully she hasn't eaten anything else we do not know about. This is especially important with her having upper and lower GI signs. Because while this could be infectious (viral, bacterial, protozoal, etc), we'd be especially concerned about gut irritation from what she ate and what could still be in the gut. Even more so since changes in behaviour like that can be a sign of pain despite her not reacting to your palpation of her belly.
With this all in mind, we need to tread with great care here. To start, if she hasn’t just vomited (since otherwise we’d need to rest her stomach for a few hours first), then you can consider treating her with an antacid. Common OTC pet safe options would be: 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), or Tagamet (More Info/Dose Here @ http://www.petplace.com/article/drug-library/library/over-the-counter/cimetidine-hcl-tagamet). Whichever you choose, we’d give this 20 minutes before food to allow absorption. Of course, do double check with your vet if she has a known health issues or is on any medications you haven't mentioned. Though I would note that if you give this and she cannot keep it down due to nausea that is usually a red flag that we need to bypass her mouth with injectable anti-vomiting medication from her vet.
If she can and steadies, we can then start her on an easily digestible diet like cooked white rice with boiled chicken, boiled white fish, cottage cheese, scrambled eggs, or meat baby food (as long as its garlic/onion free). There are also OTC vet diets that can be used (ie Hill’s I/D or Royal Canin’s sensitivity) 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. As long as improvement is being seen, I usually advise continuing this until the signs are settled, and then weaning her slowly back to her normal diet.
Finally, since there's is no blood in those stools, you can consider trying a pet safe anti-diarrheal. Pepto Bismol isn't advisable here since it can cause stomach irritation with its aspirin component. So, instead, we'd want to use something gentler on the stomach like Kaolin/Kaopectate (More Info/Dose @ http://www.petplace.com/article/drug-library/library/over-the-counter/kaolin-and-pectin-kapectolin-k-p)). This is available OTC at most pharmacies. Otherwise, Propectalin, Canikur, Fast Balance, and Protexin Pro-Fiber (all OTC at vets, pet stores, and even Amazon) would be another option. All will slow diarrhea and those last ones have the added bonus of providing support to the delicate good GI bacteria. As well, it can help to add fiber (ie canned pumpkin, all bran, etc) to her food to again bulk up feces, slow diarrhea, and help push anything else hiding in her gut.
Overall, there are a wide range of agents could trigger this GI upset we are seeing but I am concerned that these current ones are due to gut trauma from what she ate or something else lurking. Therefore, we’d want to start supportive care to settle her stomach. If she cannot keep that or water down at any point, appears dehydrated already, or doesn’t respond to the above within 8-12 hours (since she is young and there is a real dehydration risk); then we'd want to get her vet involved. They can assess her hydration, rule out fever, make sure there is nothing in her stomach that shouldn't be there or any sinister viruses present. Depending on their findings, her vet can treat her with injectable anti-vomiting medication +/- antibiotics to settle her stomach, and get her back feeling like herself.
All the best,
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