I’ve had some, uh, intestinal issues lately.  I could get more specific, if you like.  But I think I won’t.  My wife reads this blog, and I think she wouldn’t like it.  It turns out that there are pronounced gender differences when it comes to, uh, certain human odors and sounds.  Okay, so take flatus, for example.  Men and women basically pass the same amounts of gas daily.  And the gas we pass tends to be equally toxic (not very), and unpleasantly odored (though folks really genuinely do tend to think theirs personally don’t stink all that much).  But in general (with many exceptions), women tend to sneak theirs out as quietly and unobtrusively as possible.  Men, on the other hand, are more likely to let ‘er rip, possibly with accompanying humorous commentary.  (“Speak again, toothless wonder!”)  Mary Roach admits this.  She compares her own, uh, public output with that of her long-suffering husband Ed, who, she informs us, is particularly fond of brussels sprouts.  And broccoli. And unembarrassed about how his digestive tract sometimes responds to that diet.

I love knowing this stuff.  I mean, it’s interesting, is it not?  I was a Boy Scout, and spent time in summer camp, and enjoyed pork and beans for lunch.  And as is the case with most thirteen year old boys, was completely nuts about fire.  Boy Scouts are terrific pyromaniacs, which is why adult Scouting leaders have to remain ever vigilant on the subject of fire safety.  And why Smokey is a bear.  (Grown-ups think kids think bears are cool, and that kids might possibly be inclined to listen to one.)  So, yes, I’m familiar with the concept of blue darts.  When you’re a kid, there’s nothing more delightful than discovering that your body can produce fire.  But to read about the science of flatulence, the researchers who have dedicated their lives to the study of this stuff; well, it’s terrifically interesting.  And maybe a little gross.  And pretty funny, at times.

If you love good writing, if you are fascinated by science, and especially if you’re interested in the science of taboo subjects, may I recommend for your reading please: Mary Roach.  Her newest book, Gulp, is sub-titled: Adventures on the Alimentary Canal.  It’s about digestion. It’s specifically about the various scientists and researchers who study human digestion.  Which means a lot of it deals with stuff that’s gross and icky.  Which Mary Roach knows.  And which she has a lot of fun with.

In Stiff: The Curious Lives of Human Cadavers, she took on death; the physiology of it, the history of it.  Human cadavers, it turns out, have been used in all sorts of kinds of medical research; guillotined, shot off into space, crucified (to test the authenticity of the shroud of Turin.)  She had a lot of fun with all of it.  In Bonk: The Curious Coupling of Science and Sex, she explored the work of researchers into such subjects as erectile dysfunction, or zero gravity sexologists.  Now, in Gulp, it’s time to study digestion.  And answer such pressing questions as this: did Elvis really die of constipation?  Is that possible?  And what about Kurt Cobain?

She’s one of the funniest writers I know.  But also one of the most inquisitive.  Her books aren’t smarmy or gross.  She’s genuinely interested in the science of food and digestion, and in the scientists who study it.  She wants to know. About why a reputable museum has, on display, a badly engorged large intestine.  About the guy with the hole in his stomach, and his slave/master relationship with the 19th century scientist who kept studying him.  About the guy who invented the flatus-trapping underpants.  About how Elvis really did die.

And not just about good science, but also the history of digestive science, and the bad scientists who fill its pages.  We read, for example, about one Horace Fletcher, a scientist who invented and popularized the notion of ‘Fletcherizing’ one’s food.  Fletcher believed that there was essentially no such thing as excessive mastication.  He taught that every morsel of food should be chewed up to a thousand times, so that our bodies could derive every possible nutritive benefit from it.  He claimed to know someone who survived for months on a diet of 4 corn muffins and a single glass of milk, all very very thoroughly chewed.

None of this is true.  Your body does a perfectly fine job of deriving nutritive benefit from the food you eat, no matter how much, or how little, you chew it.  You don’t have to Fletcherize.  I mean, we should chew some.  Wolfing too much food too quickly isn’t all that good for you either.  But chewing the heck out of it does nothing except wear out our jaw muscles, plus it’s death on dinner-table conversation.

Mary Roach has a wonderful eye for the telling detail, plus a terrific sense of absurdity.  She writes vividly and well, and conveys the science in a readable but accurate (I suppose) way.  Best of all–and I think this is the key to her success–she gives some attention and respect to scientists working in fields where they probably don’t get much.  I think the men and women she interviews are probably thrilled to talk to her.  They’re probably excited to share their researcher with someone as personable and fair-minded as Mary clearly is.  And the result is a terrific book.

Anyway, if you’ve read other books by Mary Roach, you’ll like this one.  And if you haven’t, this is a fine one to start with. Gulp it down.  You’ll enjoy it thoroughly.  And I predict, you’ll want to read particularly fascinating or humorous passages to your significant others.  And if you’re like me, you’ll find yourself beginning conversations with stuff like ‘did you know that flatulence actually includes up to three different gasses!’  Don’t be discouraged if conversations stop dead right there.  Persevere.  This is genuinely interesting stuff.