Much attention is paid nowadays to cooking and eating, but very little to digestion and defecation. As was once true of sex, the biggest obstacle to talking about poo is the shortage of words that are neither vulgar nor medical. But just as sex is not merely for reproduction but for pleasure, shitting is a source of satisfac­tion. A book about poo may not sound particularly attractive, but Dekkers has managed to build an engaging cultural history around it. We can learn a great deal from this well-constructed discus­sion of the subject: about potty training, waste treatment, the importance of a high-fibre diet, the role of dung beetles and dung flies and the collection of guano (bird poo).

The turd does not stand alone. Dekkers shows that it is part of a world in which everything is connected, and not only in a biological sense. He does so clearly and convincingly, holding his readers’ atten­tion throughout by regularly changing tone, zooming in and out, swiftly linking past and present, and providing examples and illustrative comparisons, such as his description of the digestive tract as an underground metro network with numer­ous tracks and stations.

A good deal of space is devoted to everyday events surrounding the evacua­tion of the bowels, including constipation and other discomforts such as piles, but Dekkers manages to give his study of poo a universal twist. Metabolism is crucial to life on earth and Dekkers places it not only in a Darwinian perspective but in a cosmic context. ‘We are on earth to metabolize,’ he writes. ‘Metabolism is the source of the energy that keeps the world turning.’ It is a humbling thought. ‘Animals, plants, people: we are all playthings of the sun.’

• Shows that we’re not our brains, we’re our guts.
• Pays a great deal of attention to sociological aspects of our bowel movements, while at the same time presenting a fascinating rundown of pooing and farting in world literature.
• With style, humour and expertise, Dekkers persuades us to change our perspective.