YOU SAID:

I pooped my pants and it smelled really bad

INTO JAPANESE

私はズボンをうんざりし、本当に悪臭がした

BACK INTO ENGLISH

I was fed up with pants and really smelled bad

INTO JAPANESE

私はズボンにうんざりし、本当に悪臭がしました

BACK INTO ENGLISH

I was fed up with pants and really smelled bad