There is a bad smell in the bathroom and we don't know where it's comming from. The toilet is flushing fine. Everything else works fine there is just a smell every once in a while. The smell is in the bathroom and can't tell if the smell is comming from any one place. The house is 20 years old and all the same parts are in the bathroom (no repairs and everything works fine). WE were jsut wondering what is causing this smell and how to fix it. Thank you in advance for any advice you may have.