[Impressive picture of a melanosis coli after chronic anthraquinone laxative use--is there an increased risk for colorectal cancer?].

We report the case of a 74-year-old female with an extreme picture of melanosis coli of the whole colon after chronic use of anthraquinone laxatives for the treatment of constipation over many decades. Endoscopic work-up revealed an impressive deep black pigmentation of the whole colon mucosa which could be verified by histopathology as a widespread lipofuscin granulation. In addition, various adenomas but no colorectal carcinoma could be detected. The term melanosis coli describes a brown or black pigmentation of the colonic mucosa. Induction of melanosis coli by anthraquinone laxatives and their derivatives can be regarded as verified. The question if melanosis coli predisposes for colorectal neoplasia is discussed controversially. Based on the current literature, an association of melanosis coli between colorectal adenomas, but not colorectal carcinomas, is under discussion but the mechanisms to effect the development of colorectal neoplasia are not completely understood. Considering our case and the current scientific backround, we conclude that due to pharmaceutical side effects of anthraquinone derivatives such as electrolytic shift and water loss in addition to the risk of developing melanosis coli, anthraquinone laxatives should not be used for long-term therapy of constipation.