Your sulking inner sphincter.

It is impossible to consider toilet training for adults (see link below) without first thinking about Ignatius J. Reilly and his reactive valve.

Ignatius Jacques Reilly is something of a modern Don Quixote—eccentric, idealistic, and creative, sometimes to the point of delusion. In his foreword to the book, Walker Percy describes Ignatius as a "slob extraordinary, a mad Oliver Hardy, a fat Don Quixote, a perverse Thomas Aquinas rolled into one." He disdains modernity, particularly pop culture. The disdain becomes his obsession: he goes to movies in order to mock their perversity and express his outrage with the contemporary world's lack of "theology and geometry." He prefers the scholastic philosophy of the Middle Ages, and the Early Medieval philosopher Boethius in particular. However he also enjoys many modern comforts and conveniences, and is given to claiming that the rednecks of rural Louisiana hate all modern technology which they associate with progress. The workings of his pyloric valve play an important role in his life, reacting strongly to incidents in a fashion that he likens to Cassandra in terms of prophetic significance.

The novel is called A Confederacy of Dunces, and if you haven't read it, you must.

Meanwhile, here is some pooth.

The truth about poo: we’re doing it wrong, by Annalisa Barbieri (The Guardian)

In my large Italian family, I grew up with the subject of poo, bottoms and constipation readily – and far too frequently – discussed at the dinner table. I’d be about to raise a raviolo to my mouth, only to hear how someone’s piles had popped, just that morning.

This doesn’t mean I’m anal (sorry) about the subject. It’s fascinating away from the lunch table. Late last year, I read that we are pooing all wrong: we should be squatting, not sitting, on a toilet bowl. Then a book called Charming Bowels by Giulia Enders caused something of a storm in its native Germany and I got fully immersed in the subject.