Why is water backing up in the drains, the tub making a gurgling sound, and emitting a bad smell?

The water backing up in the drains, gurgling sound in the tub, and bad smell are likely due to a clog in the Plumbing system. This blockage is causing water to not flow properly, leading to the symptoms you are experiencing. It is important to address this issue promptly to prevent further damage and potential health hazards.