Ultimately of Australian Aboriginal derivation; named for the Belyando River of central Queensland.
The expression dates from no later 1891, from when it was in use in a shearer′s song. 
Belyando spew (uncountable)
- (Australia, slang, medicine, obsolete) An illness afflicting shearers, characterised by vomiting after meals and presumed to have been due to the hard work of shearing bent over in stifling heat (though more likely due to a local grass).
1908, Australasian Medical Association, Australasian Medical Gazette: The Journal of the Australasian branches of the British Medical Association, volume 27, page 25:
Filariasis, anchylostomiasis, tropical anaemias, and the many and varied tropical disorders, from malaria and dengue to Barcoo rot and Belyando spew, await the application of modern research methods to place them on the necessary footing to render prophylaxis and treatment more satisfactory […] .
- ^ 1970, Bill Wannan, Australian Folklore, Lansdowne Press, reprinted 1979, →ISBN