Abstract: The invention provides catheter for expanding a body passageway leading to a body cavity, such as a cervix leading to a uterus. The catheter comprises an inflatable balloon located at the distal end of the catheter. The balloon has an anterior portion and a posterior portion. The anterior portion is inflatable prior to inflation of the posterior portion.

Abstract: A device for dilating a body passageway. The device comprises an elongaed hollow shaft and a balloon at the distal end of the shaft in fluid communication with the lumen of the shaft, the balloon having at least a cylindrical portion. The balloon is formed from a flexible, unstretchable material capable of withstanding an inflation pressure of at least 10 bar. When the balloon in an uninflated state is collapsed onto the shaft the diameter of the balloon on the shaft is at most 35% of the diameter of the cylindrical portion in an inflated state.