You don't have to imagine it; you could buy one 6 years ago (http://singularityhub.com/2009/05/12/smart-toilets-doctors-i...)
And that was version 2. http://edition.cnn.com/2005/TECH/06/28/spark.toilet/index.ht... Shows you could buy one in 2005. From that description, it seems there was some room for making the thing easier to use then, though.