Why Is My Toilet Bubbling or Gurgling?

A bubbling or gurgling toilet is almost always a sign of a partial blockage or venting problem in your drain system. When water drains from another fixture (sink, shower, washing machine), it creates negative pressure that pulls air through the toilet trap — causing the bubbling sound. This can also indicate a main sewer line problem. If multiple fixtures are slow or backing up, call a plumber immediately — this is a sign of a main line blockage.