This book cover image released by W. W. Norton & Company shows "Gulp: Adventures on the Alimentary Canal," by Mary Roach. (AP Photo/W. W. Norton & Company)
This book cover image released by W. W. Norton & Company shows "Gulp: Adventures on the Alimentary Canal," by Mary Roach. (AP Photo/W. W. Norton & Company) ASSOCIATED PRESS
This book cover image released by W. W. Norton & Company shows "Gulp: Adventures on the Alimentary Canal," by Mary Roach. (AP Photo/W. W. Norton & Company) ASSOCIATED PRESS