In many young children their Eustachian tubes are not as well developed as in adults, resulting in the accumulation of fluid in the middle ear space. The two main complications that occur are less hearing as the ear drum cannot move because it is impeded by fluid and thus there is a delay in speech.
The other complication is frequent ear infection, due to the warm and moist environment where bacteria thrive as a result of the excess fluid.
A grommet looks like a button with a hole in the middle of it which is placed through the ear drum thus creating an opening through which the fluid can drain. It temporarily takes over the function of the Eustachian tube.
After a few weeks/months once the Eustachian tube has healed and is able to function normally, the grommet is naturally extruded into the ear canal.
Although it is a minor procedure a number of complications can occur such as bleeding, infection, perforation, re-insertion or even surgical removal.