We can now enjoy music, a heated seat and even a perfectly targeted spray jet while spending a penny. The history of the toilet goes back a long way and even the ancient Romans built latrines. But a special place to answer the call of nature is not enough. The result also has to be transported away. Great Inventions follows the path of this bodily waste through the sewage system to the treatment plant and beyond - and explains why the concentration of drugs in our rivers is increasing.