The pic is a bit small so I’ve transcribed the text anyway, but you can probably get the idea how this contraption was worn. The white circular bit in the centre of the picture was a smooth piece of ivory designed to fit where the sun don’t shine.
The inventor, Benjamin Atkinson, manufactured a variety of surgical mechanisms, such as prosthetic limbs and braces for curvature of the spine. Some of his inventions, including the Rectum Supporter (also known as the Anal Truss) went on display in the Great Exhibition of 1851 – presumably not modelled by someone, but who knows? It was mainly advertised in the medical press (e.g. the Medical Times and The Lancet) rather than direct to punters.
Piles and Prolapsus Ani.—The most
eminent of the Medical Profession, and thousands of persons afflicted
with the above complaints, can testify to
the advantage of ATKINSON’S REGIS-
TERED RECTUM SUPPORTER in the
curative treatment of the Piles and Prolapsus
Ani during the last nine years. It never
fails to give immediate relief, and can be
worn under all circumstances. Price 42s.,
sent free on receipt of P.O. order, with cir-
cumference of body below the waist, to B. F.
Atkinson, 3, Hemming’s-row, Charing-crs.
Source: The Medical Times and Gazette, August 22 1863