The mechanisms within conventional toilets have not changed much since they were invented, but recently a new generation of toilets has become available. Traditional toilets, or gravity toilets, work in a very straightforward manner. Water is stored in a tank above the bowl and when the flush lever is actuated, water is released under the force of gravity into the bowl and the waste is removed.

From the outside, Pressure assisted toilets look identical to gravity toilets. When you lift the lid of a pressure assisted toilet, however, instead of seeing water, you will notice an inner tank. The inner tank is completely sealed; when water is fed from the water line, the air inside the tank gets compressed. When the toilet is flushed, instead of just falling by the force of gravity, the water is forced out with the pressure of the compressed air. This pressurized stream of water cleans all the waste from the bowl much more efficiently than the water from gravity toilets. The pressure in the toilet is therefore created by using the water pressure provided by the water company - no pumps or other devices are used.

Pressure assisted toilets are still more expensive than gravity toilets, but they do a better job of removing waste from the bowl with less water. The first generation of pressure assisted toilets were very noisy and some were not very reliable; most of these hurdles have been overcome, and now pressure assisted toilets are a viable alternative to gravity toilets.