Toilet bubbles and backs up when flush
So I just bought a house and when I use the toilet in the Master bathroom, it bubbles and backs up into the toilet and then slowly drains out. I have had a plumber over to snake the drain. He snaked it 3 times all the way from the toilet flange to where the main line leaves the house. He found nothing. He said I should be good to go. Well guess what, it still does the same thing. So not only does by toilet not drain but I'm out $100. Everything else in the house seems to drain perfectly well without a hitch. I was wondering if it is a either (a) a grading issue with the drain line, or (b) do I have a clogged vent. The house did sit empty for about 9 months before we bought it. I am usually pretty handy around the house but I am stumped with this one. Please help!