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 ICD 10 Code for Melena K92.1 Codify by AAPC Classification of HES diagnoses using ICD 10 Download Scientific Diagram Melanosis coli: Symptoms, causes, treatment, and more 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 This is how laxative abuse affects colon resulting in melanosis coli .