Toilets, Sinks, Showers, Tubs and Disposals - Disposal Not Draining

All sounds fine w/my disposal (it's running/grinding), but the water does not drain out of the sink. Had to bail it out after running the dishwasher or any tap water. There is nothing in the chamber, and the blades move. The waste outlet (I think) is clear as far as my finger fits into that opening from the disposal. After I run the disposal and water, then turn off the disposal, the water bubbles back into the sink with remnants of food particles. Initially thought the dishwasher valve went out (again), but that doesn't seem to be the case. Dishwasher runs AND drains fine... into the sink!

Just checked... other plumbing (toilet, bathroom sink, basement slop sink) all draining fine, if that helps?

Any clues appreciated. I'm not handy, am poor, but need this fixed! Read I shouldn't use Drano ... options/alternatives?

Thanks,
pieper

Is your outlet from the disposer above the waste arm going out the wall? If it is below the waste arm, it won't drain. Have you checked the ptrap for an occlusion, as well as the waste arm? Do you have a double sided sink, or single?

Larry,

Thanks for your response. Ptrap has been checked... clear. Arm is where it's supposed to be (it's been all working fine for 2+ years), and my non-expert determination is that there is a clog after the trap (in the wall, heading into the basement). All other plumbing (upstairs bathroom & basement sink) are flowing fine, so I've been able to isolate the "run" of pipe that must be the culprit... and being inept and unskilled, have made an appt. with a plumber in hopes that they can unclog the clog! Wish I could try Drano, but understand that'd be the death of my disposal and/or pvc. My hunch is a plastic bag found it's way via the dishwasher or disposal or something similiar, since it was so sudden.

Thanks... and any other suggestions appreciated!

pieper