Medical devices and methods are disclosed. An example method for accessing a body lumen may include providing a catheter system. The catheter system may include a catheter shaft having a lumen defined therein and an outer wall surface having a channel formed therein. A first guidewire may be disposed in the channel and a second guidewire may be disposed in the lumen. The method may also include advancing the catheter system through a body lumen to a location where the body lumen splits into a first section and a second section, advancing the first guidewire into the first section, and advancing the second guidewire into the second section, and advancing the catheter shaft along the second guidewire and into the second section. Advancing the catheter shaft along the second guidewire and into the second section may remove at least a portion of the first guidewire from the channel.