The answer to 'my garbage disposal smells bad' is that a smelly garbage disposal is usually caused by food debris, mold, or bacteria buildup. Common symptoms include a foul rotten egg or sewage-like odor coming from the sink drain. The good news is that this is a common issue that can often be resolved with some simple DIY maintenance.
First, try running the disposal with hot water and a bit of dish soap or baking soda and vinegar to help break down and flush out any stuck-on food. You can also try using a disposal cleaner or deodorizer product specifically designed for this purpose. If the smell persists, you may need to manually clean the disposal by removing and scrubbing the splash guard and grinding components. However, if the odor is very strong or you can't seem to get rid of it, it's best to call in a professional plumber to inspect and properly clean or repair the disposal.