What does it mean to have bubbles appear in the upstairs toilet when I flush? I've never had a problem with it (no overflow or slow flow), and the main sewer line out from the house was recently reamed with a snake. Am I in imminent danger of a sewage backup? Or do I just need that line snaked out?
Thanks

The bubbles are sewer gas escaping. This indicates a partial blockage in the drain line. It should be snaked and cleared. Good luck, Tom