stomachache - a pain in a person's belly: 'most childhood stomachaches aren't serious.'
bellyache - (informal) n. a stomach pain.
(v.) [intrans.] - complain noisily or persistently: 'heads of departments bellyaching about lack of resources' ...
tummy - (informal) a person's stomach or abdomen.
pain in the stomach - Magenschmerzen
stomach ache [also: stomach-ache, stomachache] - Leibweh, Magendrücken, Magenschmerz [meist im Plural]
stomach ache [also: stomachache] - Bauchkneipen [selten], Leibschneiden [veraltet] [regional]
tummy - Bäuchlein
tummy [coll.] - Bauch
sore tummy - Bauchweh
tummy-ache [med.] - Bauchweh
bellyache - Bauchschmerzen, Bauchschmerz, Bauchweh
to bellyache about sth. [coll.] - über etw. jammern, klagen, nörgeln
backache - Rückenschmerzen [Pl., seltener im Singular - Sg.:] Rückenschmerz
I agree that it should be added, even though till and Paul failed to give any supporting evidence. Guys, next time PLEASE either support your suggestion by citing a couple of dictionaries, or use another section of the forum. Don't just put something in New Entry off the top of your head.
'Bellyache,' the only current translation given for Bauchschmerzen, is used in this sense by some people colloquially and regionally, but it's more widely used in the verb sense meaning 'to complain.'
For actual abdominal pain, 'stomachache' is by far the most common and standard term. So I would suggest marking 'bellyache' as [coll.].
The childish version, 'tummyache,' should probably also be added as one word and two words, since it's in LEO currently only in the hyphenated form which is probably least common. I would also mark it [coll.], not [med.].
At the same time, it would probably be a good idea to be sure that all the English entries for 'stomachache' show the same spelling variants. I would suggest changing the order to list the the one-word version first; it's definitely preferred in modern AE, and it's the only one NOAD even lists. I could support the two-word one as a (mostly older) variant, but does anyone really still use the hyphenated one? If it's used at all, I suspect the hyphen is BE. I would suggest checking spelling in several other AE/BE dictionaries. Someone else can do that, please (till? Paul? this was your suggestion), including giving the Merriam-Webster link, since the new i-links do not work at all for me.
Also, all the German entries for either Magen- or Bauchschmerz/en /-weh should probably handle the singular/plural issue in the same way, as should translations for similar terms such as earache, headache, and toothache.
Finally, do people really say Magenschmerz(en) for ordinary minor abdominal pain or indigestion (like what children get, used interchangeably with Bauchschmerz/en, -weh), or is that a more serious medical term that should be translated instead 'stomach pain'?
> in a U.S. school (use 'a' before a vowel _sound_, 'an' before a consonant _sound_)