A medical tube includes: a tube main body through which a conduit, through which an insertion portion of a cholangioscope is insertable, is pierced from a distal end to a rear end a side hole that is formed between the distal end and the rear end of the tube main body and causes an outer circumferential side of the insertion portion and the conduit to communicate with each other and a hardness changing portion that can change the hardness of at least a part of the tube main body including the side hole according to operation by an operator.
