We had the same problem on Orijen. Murphy had terrible gas on it and her tummy was quite distended after eating, which must have been uncomfortable. I switched her to Horizon Legacy, which is similar but doesn't have any potato. I think it might have been the potato she couldn't digest properly.
Mitchell had HORRIBLE gas on Orijen, but Matrix didn't. We switched to Acana (same makers as Orijen) and that has cut down on gas 90%. We also switched from red meat to prairie formula.
If you are using the red meat formula try the chicken or fish formulas instead.