YOU SAID:

my stomach hurts so bad it just gurgled and i pooped in the school bathrooms

INTO JAPANESE

お腹が痛くてゴロゴロと学校のバスルームでうんざりしました

BACK INTO ENGLISH

I had a stomachache and was tired of rumbling and in the bathroom of the school

INTO JAPANESE

腹痛があり、学校のトイレでゴロゴロとうんざりしていました

BACK INTO ENGLISH

I had a stomachache and was tired of rumbling in the school toilet

INTO JAPANESE

腹痛があり、学校のトイレでゴロゴロ鳴るのにうんざりしていました

BACK INTO ENGLISH

I had a stomachache and was tired of rumbling in the school toilet