No new treats by you or anyone else???
Sounds like a good Digestive Enzyme/Probiotic might do the trick to keep their gut healthy.
This one is human grade and fantastic: Sunday Sundae Nutritional Supplement
You may want to try some Slippery Elm (available at health food stores) as this coats and soothes the gut. A couple of capsules about 1/2 hour before they eat when their tummy is acting up.
If they have been on ONE dog food their whole life, they may have become sensitive to it, but strange that it would effect both dogs at the same time...doesn't make sense. The Nature's Variety has Montmorillonate Clay in it, which is similar to what the Kaopectate does for them.
There is another food on the market with Montmorillonate Clay in it
called Nature's Logic - no GMO's or synthetic vitamins: INGREDIENTS: Chicken Meal, Millet, Chicken Fat, Pumpkin Seed, Yeast Culture, Spray Dried Chicken Liver, Dried Eggs, Suncured Alfalfa Meal, Montmorillonite Clay, Kelp, Cheese Powder, Porcine Plasma, Dried Tomato, Almonds, Dried Chicory Root, Dried Carrot, Dried Apple, Sardine Meal, Egg Shell Meal, Dried Pumpkin, Dried Apricot, Dried Blueberry, Dried Spinach, Dried Broccoli, Dried Cranberry, Parsley, Dried Artichoke, Rosemary, Mixed Tocopherols, Dried Lactobacillus Acidophilus Fermentation Product, Dried Lactobacillus Casei Fermentation Product, Dried Bifidobacterium Bifidium Fermentation Product, Dried Enterococcus Faecium Fermentation Product, Dried Bacillus Coagulans Fermentation Product, Dried Pineapple Extract, Dried Aspergillus Niger Fermentation Extract, Dried Aspergillus Oryzae Fermentation Extract, Dried Trichoderma Longibrachtum Fermentation Extract
But my first choice would be the Honest Kitchen Brand Human Grade Dehydrated
food for your IBS dog if you do change. It is the ONLY
pet food in the USA that the FDA will legally allow to use the words 'Human Grade' on their packaging and advertising. Fantastic results for dogs with problems like this! All Natural Dog Food - Dehydrated Pet Food | The Honest Kitchen