The answer to 'my drain smells bad' is that a smelly drain is often caused by a buildup of organic matter, hair, soap scum, or food particles in the drain pipe. This can lead to bacterial growth and unpleasant odors. Common symptoms include a persistent foul smell coming from the drain, even after running water down it.
There are several potential solutions, depending on the severity of the issue. For minor clogs, you can try using a drain cleaner or plunging the drain to dislodge the blockage. For more stubborn clogs, a drain snake or auger may be needed to physically remove the buildup. If the smell persists even after clearing the drain, there may be a deeper issue like a cracked or damaged pipe that will require professional plumbing services.