What puppy food would be best for my 9 mo old female Aussie? She has diarrhea or very soft yellow stool off and on. We are feeding her Innova puppy. We had her checked at the vet. No worms and only mild bacteria. She was treated with antibiotics anti-acid and we put her on I/D rx food for several days. She was ok for 1 week and then off and on again. We even added a probiotic to her food, with no help. Is it common to have a sensitive tummy? Suggestions??