This book is an exploration of human digestion. Few of us realize what strange, wet miracles of science operate inside us after every meal. The author investigates the beginning, and end, of our food, addressing such questions as: why crunchy food is so appealing, why it is hard to find words for flavors and smells, why the stomach doesn't digest itself, how much we can eat before our stomachs burst, and whether constipation killed Elvis. Here we meet scientists who tackle the questions no one else thinks of, or has the courage to ask. We go on location to a pet-food taste-test lab, a fecal transplant, and into a live stomach to observe the fate of a meal. With Roach at our side, we travel the world, meeting murderers and mad scientists, Eskimos and exorcists (who have occasionally administered holy water rectally), rabbis and terrorists—who, it turns out, for practical reasons do not conceal bombs in their digestive tracts. Gulp is as much about human beings as it is about human bodies.