| This condition
is a lesion of the colon consisting of a change
in mucosal pigmentation caused by the use of
anthraquinone-containing laxatives exclusively,
since it does not occur with osmotic or bulking
and lubricant agents.
Typically it develops in the 4 months after
taking the agents and disappears in approximately
the same amount of time after ceasing them. On
endoscopy, the colon appears brown with visible
lymphoid follicles in between the paler areas
of mucosa.
Melanosis coli can present in microscopic form,
as in the deposition of pigment in macrophages
of the lamina propria, or microscopically in
the recto-sigmoid (more frequent), or it can
affect the whole colon.
It is not pathognomonic of the use of anthraquinones.
The anthraquinones are complex derivatives of
Acetyl-Co A and are contained in numerous plants.
Those molecules that possess –OH radicals
in positions 1 and 8 are the ones with laxative
properties.
Author:
Juan I Pérez Calvo
Servicio de Medicina Interna
Hospital Clínico Universitario "Lozano Blesa"
Zaragoza
Translation: Kelly
Watt |
