1. An endoscope system, comprising: a storage portion that stores image information for constructing three-dimensional image information relating to a subject that is previously acquired; a luminal organ extraction portion that, by constructing the three-dimensional image information based on the image information, extracts a predetermined luminal organ that is present in the three-dimensional image information; an image pickup portion that picks up an image of inside the subject; a position information acquisition portion that acquires position information of the image pickup portion; a position alignment portion that makes the position information acquired by the position information acquisition portion correspond to position information of three-dimensional image coordinates of the predetermined luminal organ; and an image processing portion that generates trail information based on the position information of the image pickup portion, and based on a result of the position alignment portion, creates an image in which past trail information in the trail information, insertion shape information including current distal end position information with respect to the image pickup portion, and determination information obtained by determining whether or not the image pickup portion passes through a duct in the predetermined luminal organ are superimposed in a distinguishable manner on three-dimensional image information of the predetermined luminal organ.