The invention provides an insufflation apparatus having a housing and a gas generator arranged to be, at least partially, mounted to the housing. The housing includes a gas outlet for delivering gas to a patient and a gas storage chamber arranged to store gas and deliver it to the gas outlet. The gas generator includes a cartridge mount on the housing adapted to receive a gas generating cartridge, the gas generating cartridge containing gas generating material that generates gas that is delivered to the gas storage chamber. The invention also provides alternative insufflation apparatus, a gas cartridge and a method of generating insufflation gas.