Why Does My Toilet Gurgle and Burp After Flushing?
Toilets make odd noises, such as gurgles and burps, due to the movement of air through water. Most often, the air movement responsible for such noises is due to a clogged or improperly working vent stack. These clogs cause a vacuum to form as water drains. Once the force of gravity empties the water, the vacuum pulls air through the trap.