What’s the matter?

I would say “stomach ache,” but it wouldn’t surprise me to see the other two, especially C by analogy with “headache.”

Weirdly enough, all of them are technically correct! I'm from England and round here A is by far the most common however.

D. Cramps But I would usually say C, rarely A, never B

In casual conversation over text, I'd write C, but I don't know if that's necessarily correct. It's like how "headache" is just one word.

I’ve been an English native speaker my entire life, and have never had to write stomach ache. Why are you stressing over such minutiae?

I always write A, USA English

A or C, I usually don't use a dash with this

Looks like cramps?

I always see “bellyache” as one word, so I feel like I would write “stomachache” too.

I would only ever use A; she has a stomach ache

I have spoken English my whole life and I have no idea. I cannot see how A could be wrong, but it could be C as well. When speaking they would both be the same.

A only. Australian. Also my guts are griping, if you like, or my guts hurt. Or even I've got cramps. It does seem to be more lower abdomen in the picture.

ooh no! her tumtums hurt!

We would go with option C which is stomachache as the word itself is one word. There are no hypens or spaces in between

I know my spouse spells it as one word, because he complains that it looks like it should be pronounced sto-ma-chachi.

None of those. She clearly has menstrual cramps. Stomach is a little higher.

All are OK

tummy hurt

Personally, I find C hard to read. My brain doesn't break it up properly right away, so I trip on the "achache." Maybe that's just me, though.

[I have a bad case of diarrhea ](https://youtu.be/CKjaFG4YN6g?si=x43wO9hmowCv37x8) I'd just say a stomach ache...

The word is technically stomachache. You could also use stomach ache or stomach-ache. Hyphenation in nouns is generally used if the word hasn't officially become a closed compound like stomachache. There are words in English that started out hyphenated that are now written as one word. That said, stomachache is still written hyphenated sometimes because some people feel the word is a bit awkward to the eye without it, so the old spelling isn't obsolete.

Whichever one autocorrect doesn’t try to correct 😩😩😭

As a bit of a sidenote that I haven't seen anyone else comment on, however you want to write it? At least in my dialect of US English, that particular sentence wouldn't sound natural with no article. "She has A headache", rather than "she has headache". It's the same talking about other parts of the body.

It really, truly, does not matter.

I would use tummy ache over stomach ache, bit this might be a UK vs US variation

she has a .............. positive pregnancy test, holy shit, how f'ing far must I travel to get an abortion now?

as a native, I do not care about the spelling of this word/phrase

I always write A, USA English

Pussyache