A method for performing a medical procedure may comprise advancing a first device through a first body lumen. A distal portion of the first device may include a magnet. The method may further comprise advancing a second device through a second body lumen. The second device may include a magnetic field sensor. The method may further comprise_receiving a signal from the magnetic field sensor. The signal may be indicative of a magnetic field measured by the magnetic field sensor. The method may further comprise, if the received signal matches a magnetic field of the magnet, identifying a position of the magnet.