Recs on similar nutrition value but better quality than Hill's?

We have a 14 months old male Boxer and we've been feeding him Acana Puppy & Junior formula. In the past couple months, his stools have been soft and in the last month they were basically diarrheas. Not to mention the minute-apart gas that's just lethal.

On the advise of our vet, we fed him Hill's Prescription Diet i/d Gastrointestinal Health dogfood for about 2 weeks. He loved it and his bowel movement improved tremendously. He pooped way less in frequency and volume, the poops were firmer and darker, and he farted waay less often and stinky.

Now he's been back on Acana for a few days and everything went back to s**t. I wonder if he actually benefits from lower protein diet (Acana is 32% and Hil's is 23.2%) but I want to find a better formulated one than Hill's.

We live in Malta and options are limited but we would appreciate any suggestions. TIA!