IAMS Advanced Nutrition Adult Large Dog - Chicken - dog dry food

My four year old, 45kg (Harrier and Welsh hound cross) dog suffered from terrible flatulence and constipation after consuming IAMS for three weeks. He was fine initially, it was only after the third week that his problems emerged. He enjoyed the taste of the kibble but it just didn't agree with him. I had to put him on a bland diet of rice and chicken to get him back to normal. The price point is extremely competitive, and the taste fine, but unfortunately the ingredients did not suit him.