Melanosis Coli Clinical Gastroenterology and Hepatology Melanosis Ilei Clinical Gastroenterology and Hepatology This is a very rare case of metastatic oral mucosal melanoma to the colon with an unusual presentation mimicking melanosis coli. The colonoscopy findings show no mass effect but multiple hyperpigmented lesions Pathology Outlines Melanosis coli Pathology Outlines Melanosis coli 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