Blocked drain - happens to me (my toilet) from time to time. Blockage always outside the house. Lift cover of inspection pit and use a stick to pull obstruction back into pit. After a few mins work the water suddenly drains away. Exit pipe and blockage will be in direction of the street more or less. Use hose pipe to clean up the pit walls. Replace cover. Wash hands thoroughly.
It's possible that your blockage may be in the S-bend trap indoors - but if you have a manhole outside then look in there first.
If you try to push the blockage further along the drain pipe you may have much more work to do - pulling backwards is easier and quicker.
Good luck...
Peccavi, July 2013
