“Melanosis” in the small and large intestine 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 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 Chronic California herbal tea use causing biopsy proven Melanosis coli Segenet Bizuneh, Shibabaw Fentahun, Gebrehiwot Lema, Andinet Azaje, 2024 Bring Awareness to Crohn's and Colitis in December AAPC Knowledge Center