I would add in qualtiy probiotics, and use a food that does not have grains in it. Dogs can have problems with different types of food, but grain is high on the list. Now, I can't do grain free kibbles without adding in extra well cooked veggies b/c my guys need a little more fiber (don't ever use onions, don't use alot of broccolli or spinach at any one time). A note about aloe vera juice: it has to be a special kind that has been processed to rid an ingredinet out of it. Normal aloe vera juice will actually cause diarrhea. I did try it once in small amounts.
Another thing would be to give slippery elm to coat the stomach. I don't recommend using it long term b/c coating the stomach will reduce the nutrient absorption, but to help in healing the gut and giving it a break while it heals might be helpful. I use NOW brand capsules and can take out of capsule and add in a small bit of water and he should lap it up. Otherwise, can use the capsule about an hour before mealtime.
Away from mealtime, use l-glutamine (NOT l-glutamate). Remember the "mine" part is good, as in "healing "my" stomach. It shoudl help to heal the intestingal lining. I had to use the l-glutamine and Good probiotics to help my allergy girls stomach. I hope this helps.