Sanitation is rarely discussed—after all, what we do with toilets is not usually a topic for polite company. For some of us, the very existence of World Toilet Day seems like a joke. The problem is that many people don’t have a toilet, or any other form of sanitation. In fact, 2.6 billion people don’t. It’s a basic service – and a fundamental human right – that most of us take for granted, but one that is currently denied to 40% of the world’s population.