First off, a failure with BB doesn’t mean anything except a failure with BB. Lots of people report BB doing the same thing to their dogs even when their dogs are already eating grain free.
The first food I would suggest is NutriSource. They have a chicken and rice that is well tolerated by many dogs. They also have other formulas that are also well tolerated. Next, I would tell you that no matter what you feed you should put your dog on probiotics and digestive enzymes. Find a probiotic with at least 12 different strains, more is better. Swanson’s makes a great probiotic at a great price and they have enzymes too. These 2 items will help heal his gut and do some of the work of digesting food for him. Next, try pure canned pumpkin for loose stools, not the pie filling, it has spices that are not great for dogs. Also add water to his meals to soften up the kibble so his digestive juices can do their work quicker, and add apple cider vinegar with the mother to his food, 1 tsp per 2 cups of food, this helps with protein digestion. Finally, when you find a kibble that works for him, if he starts turning his nose up at it then it is OK to add canned food to keep him interested, actually it’s good to add some canned food or fresh foods to kibble anytime.
BTW, rotating foods helps support a wider variety of probiotics in the stomach, which in turn helps many dogs with sensitive stomachs to get better and not be known for their sensitive stomach anymore.
You may need to start watching what ingredients are in the foods he does well on versus the foods he doesn’t do well on to see if you can determine if some of his problem is food intolerances.
Good luck!!
