Douglas Harper's Etymology Dictionary
Usage examples of "stomach-ache".
For the relief of flatulent stomach-ache, whether in children or in adults, from five to fifteen drops of the essence may be given on a lump of sugar, or mixed with two dessertspoonfuls of hot water.
So he stood up and raised his hand, and said to the schoolma'am, "Please, ma'am, I 've got the stomach-ache.