Melanosis Coli El Atlas Gastrointestinal gastrointestinalatlas.com Melanosis coli** Melanosis coli is a benign, reversible condition characterized by brown black pigmentation of the colonic mucosa, most often due to chronic use of anthraquinone laxatives. The discoloration is caused Colonic melanosis due to excessive consumption of laxatives containing anthraquinone and senna : r MedicalGore Molecular diagnosis of viral hepatitis Gastroenterology