Melanosis coli: A comprehensive review

Melanosis coli (MC) is a common condition characterized by a black or brown pigment deposited in the colorectal mucosa. It is a reversible condition that is influenced by many factors, such as living habits and bowel function. However, the epidemiology and etiology of MC are still unclear. Most studies show that there is a significant correlation between the use of anthraquinone laxatives and the occurrence of MC. At present, the mechanism of the apoptosis theory is widely recognized as regards the pathogenesis of MC. There is no specific clinical manifestation of MC, and its diagnosis is mainly based on a complimentary examination, such as endoscopic and histopathological tests. General treatment, such as changing living habits, is preferred, and medical or surgical treatment should not be considered in the absence of serious malignancy. The aim of this review is to systematically present and outline the concepts of the epidemiology, etiology, histopathology, pathogenesis, clinical manifestations, diagnosis and treatment of MC, in order to improve the understanding of this condition.