I love Mary Roach. I will read whatever she writes, regardless of whether or not the subject area really sounds interesting to me. I was admittedly indifferent to this one, generally speaking, before I picked it up. The Read Harder challenge said to read a non-fiction book about science, and I knew Mary Roach was my gal for this.
I enjoy Mary Roach’s smorgasbord approach to non-fiction writing. Each idea is linked to the next, but if you look at them from the macro you wouldn’t necessarily be able to predict how. Roach’s tone is respectful while simultaneously playful, and brightens up some perhaps less than pleasant topics. 
In her fifth book Roach tackles something we all share: the alimentary canal. Gulp takes us inside the body, a tour from mouth to rectum with Roach answering the random questions this passageway provides. The questions inspired by our insides may be taboo, (as were the cadavers in Stiff) and a bit surreal (zero gravity pooping anyone? See Packing for Mars), but Roach has found her niche as the purveyor of answers for the taboo and surreal. Thank goodness.
Read this book if you want to know why is crunchy food so appealing, or why is it so hard to find names for flavors and smells. What about the stomach digesting itself? How much can you eat before your stomach bursts? Can constipation kill you? Did it kill Elvis? (You know you want the answers to all of these questions.)
Why the three-star rating if I obviously enjoy Roach so much? This book, believe it or not, suffers from a lack of images. We can’t see our alimentary canal, and a lot of the procedures that come up in Roach’s research were a bit difficult for me to follow along. I was also suffering through a bout of the stomach bug and some small food poisoning, so this may not have been a timely book for me. But it actually made me feel better to burp along with Roach’s narrative.