When you flush your toilet, the bowl should not gurgle or burp as the water exits and new water begins to refill the bowl. Gurgling and burping in a toilet's bowl indicate the presence of a larger problem that you must address so your toilet and other plumbing fixtures in your house function properly.
Vent Pipe Functions
The vent pipes in your house's plumbing system perform two functions. The vent pipes allow the sewer gasses in the pipes in your house to escape through the roof, keeping the gasses from going into your house where they can cause health problems. Vent pipes also help replace air pressure in the house's plumbing, keeping the water levels in the different plumbing fixtures stable and the water flowing smoothly through the drainpipes.
An obstruction in the vent pipe that connects to your toilet's drainpipe will cause the gurgling and burping when you flush. Sometimes leafs, dead animals, parts of the vent pipe, snow and other debris fall into the vent pipe and plug it up. To check for obstructions yourself, you must climb onto the house's roof where the vent pipes exit. Locate the vent pipe for your bathroom, and shine a flashlight down it to check for obstructions.
Clearing It Yourself
Once you have spotted the obstruction in the vent pipe, try clearing it out yourself. Some obstructions sit on the top of the vent pipe, making removing them easy. If the obstruction sits inside the pipe, use a flexible retrieval tool to pull it out. If you cannot reach the obstruction, use your garden hose to wash it out of the pipe. Use the high-pressure attachment for your garden hose so you have a better chance of freeing the obstruction.
If you cannot get rid of the obstruction yourself, of if you do not see one at all, contact a local plumber. Plumbers have long augers or snakes that will feed through your house's vent pipes, allowing them to free obstructions you cannot even see. Plumbers also will use a device that produces fake smoke, which the plumber sends through the vent pipes in your house to identify the location of blockages and even breaks in the vent pipes.