1) a pain in my innards

我肚子疼.
2) I have a pain in my abdomen

我肚子疼
3) There is something wrong with my stomach.

是我肚子疼。
4) I have a headache and a stomachache.

我头疼,肚子疼。
5) I have a bad stomachache.

我肚子疼得厉害。
参考词条