Try to unclog the toilet using a plunger with an extension flange to get a good seal. Begin with a gentle plunge to avoid blowing water all over the bathroom. The initial bell is full of air, requiring a gentle plunge to avoid air being forced back around the seal. Plunge vigorously once the air is forced out while keeping the seal in place. Ensure that the water level in the bowl covers the plunger for the best result.
If this does not work, try using a plumbing snake to remove the blockage. Feed the wire into the toilet until it reaches the clog, and then turn the snake in the clockwise direction. This should break up the clog or hold it in place to be pulled out.
The last resort is to pull up the toilet. Begin by disconnecting the water supply and unscrewing the toilet from its mounting ring. The blockage should be visible and easy to remove at this stage. Replace the mounting bolts and wax ring with new ones when re-assembling the toilet. A professional plumber may be needed for clogs that are out of reach.Learn more about Plumbing