does anyone know what kind of disease the Pāli word kucchiroga (skt. kukśiroga) stands for? 

Or is it only a collective term for several diseases? I found as translations: disorders of abdomen,

 abdominal trouble, belly-disease.

In Mahāvaṃsa 37.113 a snake has this disease, and it has a swelling or boil (gaṇḍa) on its belly.

Monks from Sri Lanka who travelled to India in 1852 and the following years

fell ill with kucchiroga after  their arrival in Nāgapaṭṭa, India. Several of them died.

Any information is welcome,

Petra Kieffer-Pülz