Is there something wrong with my baby??

My babies poop smells so bad. I know poop smells bad but oh my gosh its almost frustrating how bad his poop smells. Its so bad and im not being dramatic that even when there's just a skid mark of poop you can smell it from across the room. There can be a pea size in there and its hard to breath changing his diaper. I have 2 other kids so poop doesnt bother me. But his im concerned for. Why is this? He had a healthy diet.