Abuse of laxatives and melanosis coli Melanosis coli: a case report The Egyptian Journal of Internal Medicine Springer Nature Link ICD 10 Code C18.7: Malignant Neoplasm of Sigmoid Colon Pabau Melanosis Coli: A Case of Mistaken IdentityA Case Report The Permanente Journal ICD 10 CM TRAINING July 16, 2013 Melanosis coli is dark brown black pigmentation of colorectal mucosa associated with chronic use of laxatives containing anthraquinone. Examples of such laxatives include senna and rhubarb derivatives. Clinical Importance: There is no association