[History of "rang", an ancient disease entity].

The title of "rang" was first appeared in Shi You's Ji jiu pian in which there is a sentence saying that "thirst, vomiting, nausea, coughing, panting, and rang". It refers to dysentery. Later, many other derivatives, including "rang dysentery", "niang dysentery" and "niang du dysentery" etc. appeared. "Rang li" refers to chronic dysentery; "niang li" and "niang du li" refer to stagnation resulting in mass formation. All these titles are of the same definition, viz. referring to the development of "rang", or dysentery. However, careful analysis may also reveal different meanings, but without clear demarcation. They can be applied for the same disorders.