I have this problem every few months. You may have a blocked toilet pan but the issue I get is a blockage of the pipe leading from the inspection pit outside the house. Foul water builds up in the pit and back pressure stops the toilet pan from draining quickly.
I take the lid off the pit and use a piece of plumbers barrier pipe about 2M long both stiff and flexible enough to poke the obstruction away. Then a quick hose down.
It's a ten minute job. If it is your pan that's blocked you can get a drain cleaning spring that will go around the bends in the pipework from a good DIY or hardware store.
Or use a plunger...
Peccavi
February 2009
Go to the hardware shop and get a "plunger". This is a handle with a rubble device on the end. The put the rubber end down the loo and give it a couple of quick pump like strokes. This generates pressure and would normall remove any blockage. Good luck!
bill
February 2009
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