Toilet wont flush? help!?

Single story house on a slab one bathroom the toilet wont flush it just fills up and will go down real slow like an hour or two, unless you plunge it then it'll go down I had it snaked from main drain didn't do anything cleaned stink pipe to, anyone have any ideas how to fix this? Does it sound like air problem or a blockage? Also it did backup into the tub to but after I plunged it, its been working fine.