Melanosis coli: a contrast effect or an oncogenic effect? A large scale retrospective cohort study International Journal of Colorectal Disease Springer Nature Link 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 Experimental and Therapeutic Medicine 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