Just how and why did Elvis Presley die on the toilet? What is a “prison wallet”? Which sex is the greater offender flatulence-wise? If these are the kinds of questions that consume you, you will gobble up Mary Roach’s “Gulp.” As with her earlier inquiries into dead bodies (“Stiff”), sex (“Bonk”), and outer space (“Packing for Mars”), Roach approaches her topic with robust curiosity and ready humor. Here she takes on digestion, broadly defined as everything that happens from the moment a diner sits down to a meal to the moment that diner, well, sits down again. Some of what Roach writes about breaches the boundaries of polite conversation — though she insists, “my aim is not to disgust” — but it’s also endlessly entertaining.
The story starts, somewhat surprisingly, with the nose, an underrated organ in the narrative of eating. But smell is where taste begins, Roach points out, and the sense plays a large role in the strange science of flavor consulting, as the author discovers when she auditions for a gig sniffing and rating various olive oils (she fails to make the cut). Roach is a fan of the field trip, visiting a pet food company (where she learns that dogs are very fond of the smell of cadavers and decomposing proteins in general), a laboratory studying saliva (where she follows spit-collecting instructions that include, “Gently chew the tampon for one minute”), and a professor in Minnesota whose entire academic career has been devoted to studying intestinal gas. She’s game to participate as well as observe, and finds the experts in these relatively lonely fields are usually quite eager to talk: “You get the sense oral processing experts are not, generally speaking, besieged by media inquiries.”
Following the general pathway of the alimentary canal, Roach progresses through tasting and chewing to swallowing, digesting, and excreting. There are digressions, of course, to ponder the viability of survival after being eaten alive (a la the Bible’s Jonah and the whale story), as well as the related question of whether animals such as snakes and frogs occasionally inhabit our stomachs. Scientific consensus: The “bosom serpents” and stomach frogs of the 19th century represented either hypochondria or mundane tummy troubles, mostly gas. Speaking of gas, Roach’s research reveals (in a Canadian journal article) the answer to a question that has troubled many marriages: Men are responsible for “a greater volume of gas per passage,” while women’s emissions were “deemed to have a significantly worse odour.”
As Roach hits the home stretch of our digestive journey, some truly outrageous facts emerge. There is that “prison wallet,” for one, a slang term for the use to which incarcerated smugglers put their rectums: Cellphones and chargers are popular, but one warden tells Roach of an inmate caught with “two boxes of staples, a pencil sharpener, sharpener blades, and three jumbo binder rings.” As for the first question posed here, Roach talks to Elvis’s longtime personal doctor about the star’s intractable constipation, leading to a condition called megacolon — “a colon two to three times normal size,” according to the autopsy report — which, in turn, likely led to death while, to borrow the King’s personal motto, “Taking Care of Business.”
Even amid sad stories like this one, it’s hard not to succumb to the childlike amusements of bathroom humor. Sure, there are times when Roach strains for jokes that don’t quite land. But for the most part, “Gulp” is a delicious read and, dare I say it, a total gas.
Kate Tuttle, a writer and editor, can be reached at firstname.lastname@example.org.