"It's an unlikely topic perhaps but, for me, that in itself is a good enough reason to take a closer look at the subject," says Ifor ap Glyn, presenter and producer of the new series Tai Bach y Byd (Toilets of the World) which starts on S4C on Thursday, 26 April.
"We're talking about something which affects all of us and in more significant ways than you'd think."
Ifor goes in search of interesting toilets in China, Japan, Bangladesh, Spain, the Netherlands and England, but he begins with the story of the Welsh loo at the end of the garden.
"We will look at the history of the toilet - did you know that toilets are mentioned in the Bible? We will discover how the design has changed over the years, in our society and in other countries. The type of toilet we have says a lot about us.
"If you go on holiday to France and have to use the simple 'hole in the ground' toilet, you are forced to temporarily change your habit - which of course means to squat instead of sit.
"The truth is that this is the norm for much of the world, and it isn't the only custom which divides us. Chinese people write poems around the doors of their toilets. In the Netherlands they try to encourage women to pee standing up. And in the USA they used to use corncobs to wipe their bottoms!
"The four part series will be light hearted, but the subject will not be treated as a joke. Although we do visit the Golden Poo Awards which celebrate toilet humour - but as a means of raising awareness of the fact that there are 2.6 billion people in the world without a toilet.
"Bangladesh was the most interesting country we visited - it's the poorest country we saw where toilets are rare. We saw a scheme by BRAC (Bangladesh Rural Advancement Committee) which helps people build their own simple toilets and educate why it's so important to use them - simply because it reduces diseases. People live longer in societies where toilets are common."
Ifor's visit to Japan, and the sophisticated toilets they have there was a completely different experience.
"The toilets there look more like aeroplane cockpits than anything else. They have heated seats and sprays to clean your bottom with different settings to control the water power and temperature. They are amazingly complicated and you will see how I made a right mess of using one - there was water everywhere!"
