Best-selling author Mary Roach 81 has just published her latest gift to readers, Gulp: Adventures on the Alimentary Canal (W. W. Norton), in which she takes a memorable tour inside and outside of the body. Her fascinating book on the process of eating brings readers upclose with the bodily equipment that turns food into the nutrients and sustenance that keeps us ticking. On her quest for knowledge of the digestive tract, Roach meets with professors and technicians, murderers, mad scientists, Eskimos, exorcists, rabbis and other unique characters. She is fearless in asking taboo and embarrassing questions with relish and humor.…