<Li> Being located at a household level or in public (toilet room versus public toilet) </Li> <P> People use different toilet types based on the country that they are in . In developing countries, access to toilets is also related to people's socio - economic status . Poor people in low - income countries often have no toilets at all and resort to open defecation instead . This is part of the sanitation crisis which international initiatives such as World Toilet Day draw attention to . </P> <P> A typical flush toilet is a ceramic bowl (pan) connected on the "up" side to a cistern (tank) that enables rapid filling with water, and on the "down" side to a drain pipe that removes the effluent . When a toilet is flushed, the sewage should flow into a septic tank or into a system connected to a sewage treatment plant . However, in many developing countries, this treatment step does not take place . </P> <P> The water in the toilet bowl is connected to a pipe shaped like an upside - down U . One side of the U channel is arranged as a siphon tube longer than the water in the bowl is high . The siphon tube connects to the drain . The bottom of the drain pipe limits the height of the water in the bowl before it flows down the drain . The water in the bowl acts as a barrier to sewer gas entering the building . Sewer gas escapes through a vent pipe attached to the sewer line . </P>

What the back part of the toilet called