Why would a toilet gurgle and bubble when flushed?

Answer:

Answer

It's probobly the flapper on your toilet. It may not open wide enough allowing air pockets to go through your toilet. Try adjusting the chain from your trip lever to your flapper.

Answer

I know of a few possible reasons why this could happen:

1 - the tube from the refill valve is not properly seated at the overflow pipe, or the refill rate is too high or low

2 - the vent pipe for the waste system could be clogged or partially clogged, either at the roof (bird's nest, etc) or at one of the fixtures (gummy sealing stuff).

3 - vent pipe could be too small for your climate (frosts up, limiting water movement)

4 - there could be a crack in the toilet even a little crack can cause these problems

1 - you can fix yourself by adjusting the hose and/or adjusting the screw atop the ballcock and testing the adjustment til it's right and there's no gurgle

2,3 - you should get a professional to do this since your home snake could be too short or wimpy, or need other equipment or experience.