Postmortal Haemorrhoids

Rotten up to pieces, but something left behind.
Rectal autopsy complete, but what it is to be found?
Postmortal haemorrhoids, breeding pustules,
To infect and putrify all the body.

Inherited piles, leaking white fluids, reeking grose odours
And infecting all within their range.

Pustulated corpse on the postmortem surgery table.
Cause of death: haemorrhoids from unidentified source.

Within two weeks proves this et
Sickness to be fatal: haemorrhoids spreading from anal skin
To guttural areas, rotting the victim from within.