It has become a weed in a number of tropical areas of the world, including Australia, where it has been introduced.
Bellyache bush occurs across northern Australia, but never in the south.
It is naturalised in Queensland, particularly along the Burdekin river, where it has taken over extensive areas of river frontage. Infestations can range from isolated bushes and small clumps, to infestations covering many hectares. In WA it is found in parts of the Kimberley region. It appears to be spreading slowly in all northern states, and seems to be associated with pressures of overstocking, less frequent use of fire as a pasture management tool and the availability of disturbed sites around towns. Bellyache bush may have been deliberately introduced into Australia late last century for medicinal or ornamental purposes.