"Gulp: Adventures on the Alimentary Canal" is a non-fiction book by Mary Roach that explores the human digestive system. The author takes readers on a journey through the alimentary canal, detailing how food is processed from ingestion to excretion. In her signature engaging style, Roach combines scientific facts with humor and anecdotes. She discusses various topics, such as the role of bacteria in digestion and the history of gastronomy, making complex concepts accessible and entertaining for readers.