Melanosis coli is the presence of dark brown discoloration of the lining of the colon (colonic mucosa). The most common cause of melanosis coli is the chronic use of herbal laxatives that contain anthraquinones.
Melanosis coli is generally considered to be harmless, although the question of whether the condition increases the risk of colorectal cancer has been raised without any clear-cut conclusions to date. Most gastroenterologists consider it to be harmless.
Melanosis coli may be seen as early as four months after regular use of herbal laxatives, but will disappear within six to twelve months after laxative use has stopped.
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