Melanosis coli

Melanosis coli
Other namesPseudomelanosis coli,
Melanosis coli identified on colonoscopy as a brownish moiré pattern on the wall of the colon.
Micrograph of melanosis coli, with the characteristic mucosal lipofuscin-laden macrophages (brown).

Melanosis coli, also pseudomelanosis coli, is a disorder of pigmentation of the wall of the colon, often identified at the time of colonoscopy. It is benign and may have no significant correlation with disease. The brown pigment is lipofuscin in macrophages, not melanin.[citation needed] It is most commonly associated with the use of certain laxatives.