YOU SAID:

I have a bad case of the bad pain the in stomach ache.

INTO JAPANESE

腹痛がひどい痛みの悪い症例があります。

BACK INTO ENGLISH

I have a bad pain of abdominal pain.

INTO JAPANESE

腹痛がひどいです。

BACK INTO ENGLISH

My stomachache is terrible.

INTO JAPANESE

私の腹痛はひどいです。

BACK INTO ENGLISH

My stomachache is terrible.