The irresistible, ever-curious, and always best-selling Mary Roach returns with a new adventure to the invisible realm we carry around inside.

"America’s funniest science writer" (Washington Post) takes us down the hatch on an unforgettable tour. The alimentary canal that Gulp explores is classic Mary Roach terrain: the questions inspired by our insides are as taboo, in their way, as the cadavers in Stiff and every bit as surreal as the universe of zero gravity explored in Packing for Mars. Why is crunchy food so appealing? Why is it so hard to find names for flavors and smells? Why doesn’t the stomach digest itself? How much can you eat before your stomach bursts? Can constipation kill you? Did it kill Elvis? In Gulp we meet scientists who tackle the questions no one else thinks—or has the courage—to ask. And we go on location to a pet-food taste-test lab, a bacteria transplant, and into a live stomach to observe the fate of a meal. With Roach as our insatiably curious guide, we travel the world, meeting murderers and mad scientists (one is a certain Dr. McNaught, who gleefully sets fire to a young man’s belch), Eskimos (with whom Roach eats the eye of an Arctic char) and exorcists (who have occasionally administered holy water rectally), nuns, terrorists (who, it turns out, for practical reasons do not conceal bombs in their digestive tracts), scammers and schemers, and so we learn about ourselves.

Like all of Roach’s books, Gulp is as much about human beings as it is about human bodies.