The answer to 'my garbage disposal smells bad' is that a smelly garbage disposal is usually caused by food buildup, mold, or bacteria. This can happen if the disposal isn't used regularly or if food debris gets stuck inside. Symptoms include a foul odor coming from the sink drain.
To fix a smelly garbage disposal, you can try running it with lemon or vinegar to help break down the buildup. You can also use a disposal cleaner or deodorizer. If the smell persists, you may need to disassemble and clean the disposal thoroughly. However, if the issue is more serious like a clogged or damaged disposal, it's best to call a professional plumber to diagnose and repair the problem.