My husband tends to not eat as much brown rice and pasta. He likes it but I think it also bloats him. Eat less grains and see if it still happens. If it does then it's not the grains. I know I get that way with wheat products and have always thought it was normal until my husband's mom told me all about her 'candida' stuff. She still can't eat sugars at all (except some fruits). She can't eat wheat at all.
I'm doing a slight candida diet starting the beginning of the year to see if it helps me.
I hope you figure out the problem!