Medical devices and methods for making and using medical devices are disclosed. An example medical device may include a medical guidewire including a core wire. The core wire may include a distal constant diameter, a first tapered section, an intermediate constant diameter section, a second tapered section, and a proximal constant diameter section. The distal end of the first tapered section may be attached to the proximal end of the distal constant diameter section such that a first inflection point is defined where the distal end of the first tapered section and the proximal end of the distal constant diameter section meet. The core wire may be configured such that when a first predetermined longitudinal force is applied to the distal end of the distal constant diameter section along the longitudinal axis, the distal constant diameter section prolapses such that a first loop is defined about the first inflection point.
