Melanosis coli is a condition where the inner lining of the colon turns dark brown or black, usually due to long term use of certain laxatives #doctorsdiary #askdoc #doctorsofinstagram Melanosis Coli in Pigs Coincides With High Sulfate Content in Drinking Water Irene M. Rodrguez Gmez, Jaime Gmez Laguna, Ins Ruedas Torres, Jos M. Snchez Carvajal, ngel V. Garrido Medina, Gabino Roger Garca, Librado Carrasco, 2021 HEPATITIS C 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 Sofosbuvir and Velpatasvir for HCV Genotype 1, 2, 4, 5, and 6 Infection New England Journal of Medicine