An endoscope with guiding apparatus is described herein. A steerable endoscope is described having an elongate body with a manually or selectively steerable distal portion, an automatically controlled portion, a flexible and passively manipulated proximal portion, and an externally controlled and manipulatable tracking rod or guide. The tracking rod or guide is positioned within a guide channel within the endoscope and slides relative to the endoscope. When the guide is in a flexible state, it can conform to a curve or path defined by the steerable distal portion and the automatically controlled portion. The guide can then be selectively rigidized to assume that curve or path. Once set, the endoscope can be advanced over the rigidized guide in a monorail or “piggy-back” fashion so that the flexible proximal portion follows the curve held by the guide until the endoscope reaches a next point of curvature within a body lumen.