Right now, with NASA flying helicopters on Mars and SpaceX planning new spaceports, off-world exploration is the thing. But for many kids, the airless void beyond Earth’s atmosphere can never quite match the fascination they have with the squishy, noisy, smelly workings of their own inner spaces. After all, the first question young people often have for an astronaut is: how do you pee and poop in zero gravity?

The mysteries of what goes on under our skin – especially what happens to all the food and drink we ingest – is the focus of a new science book by Jennifer Gardy, who has worked at the B.C. Centre for Disease Control and currently studies malaria under the auspices of the Gates Foundation. Over eight info-packed chapters, Gardy breaks down (no pun intended) the dizzyingly complex processes by which our bodies extract every nutrient-rich molecule from our food, protect us from harm, and, as a side benefit, entertain us with the resulting waste and off-gassing.

It Takes Guts is as much a travelogue as it is a science book, charting a busy and occasionally perilous journey from the mouth to the anus. Gardy starts by exploring, in depth, the complicated procedure that is chewing, along with all its attendant features (saliva, teeth, tongue, taste buds, and epiglottis), then moves through the esophagus, stomach, and small and large intestines, until finally arriving at the big event, where turds – fully depleted of all things useful, and in a handy solid form – get pushed out into the world.

As with most travel narratives, It Takes Guts is all about the weird and delightful things that happen along the way. Gardy explains – in a friendly, wanna-hear-something-cool? tone that never devolves into gross-out humour – why we can’t sneeze while chewing, how sword swallowers do their thing, how farts happen, and why corn niblets often make it through the digestive process intact. Oh, and she covers going to the bathroom in space too. For such a short book, It Takes Guts is nearly encyclopedic and yet moves smoothly from fact to fact without feeling overstuffed.

Vancouver illustrator Belle Wuthrich’s lighthearted images achieve the same balance of fun and dignity as Gardy’s prose: we get anthropomorphized poops and rainbows in toilets, but the illustrations never feel juvenile, in the negative sense of the term. Neither do the images ever overwhelm the text – the remarkable journey from food to feces, and the many biological miracles that occur along the way, remain the main focus. Gardy has digested an impressive amount of information to produce a highly polished gem of a book.