I have two neutered 8 year old domestic long haired cats. One has a history of bladder infections/crystals so both cats are now on Urinary SO by MediCal. They have been on the food since July, with no bladder issues. However, I have heard both of their stomachs growl. Or it could be their intestines, not exactly sure. But I'd like to know is it because of the food? And if so, what are my options for an alternative? I was told that once a cat has had crystals, Urinary SO is the only food they can eat to prevent crystals in the future. But, if both cats are constantly hungry or gassy I'd like to switch foods. And they burp a lot too. Thanks!