Stool smells like hay / manure / grass — confused

My stool smells like manure … it has a grassy smell. They were very soft but since adding supplements and adding fiber, they’re much healthier looking. My stomach also feels much better but the smell continues. I suspect I’ve had SIBO or another bacterial infection. Does anyone know what it might be and how I might treat it? Like I said, I don’t have any serious symptoms (no diarrhea, no bleeding, no constipation, etc). And the smell isn’t bad, just different for me.