Adventures on the Alimentary Canal

I write about a lot of depressing subjects, and sometimes a change of pace is welcome. Mary Roach, billed as “America’s funniest science writer,” has followed up on her earlier explorations of cadavers (Stiff), sex (Bonk), the afterlife (Spook), and survival on spaceships (Packing for Mars) with a new book entitled Gulp: Adventures on the Alimentary Canal.

Forget all that mythology about diet, detoxification, and 10-year-old hamburger accretions in the bowel. The reality of human digestive physiology is far more interesting and has the extra-added attraction of being true. And in Roach’s hands, often howlingly funny.  She is a hands-on investigative reporter who is ready to try anything; among other adventures she inserts her entire arm in a cow’s stomach. Her highly entertaining odyssey takes her to Igloolik to eat narwhal skin, to a dog food tasting lab in Missouri, to Minnesota to observe a fecal transplant, and to strange and exotic outposts at the cutting edge of science, populated by colorful characters.

She also delves into intriguing vignettes of history. Did you know that when President Garfield was dying from complications from an assassin’s bullet, he was fed exclusively by rectum? She gives the recipe and describes the offensive odors that pervaded the whole house.

She describes how the Catholic Church grappled with the question of whether rectal consumption of beef broth would break one’s Lenten fast. Pharmacists had been selling bouillon enemas to nuns and other pious Catholics to sustain them through the fast. According to the Vatican rules on fasting, food was defined as passing through the mouth, so nourishment by enema was apparently okay. But they weren’t entirely sure, and they actually considered applying the scientific method to matters of faith:

An experiment was proposed whereby volunteers would be fed strictly by rectum. If they survived, the enema would have to be considered food and therefore banned. If they didn’t, the definition would remain as is, and some vigorous penance would be in order. In the end, nobody volunteered and the nuns continued…to welcome the clysters.

Roach tells us that hydrogen sulfide, the odor of rotten eggs, is as lethal, molecule for molecule, as cyanide. It is offensive to our noses at 10 parts per million, but above 150ppm we can no longer smell it: it paralyzes the olfactory nerves. It can reach 1000ppm in manure pits, enough to cause respiratory paralysis and suffocation. Without the odor to warn them, people collapse and die, as do those who try to rescue them. In one case, a farmer went into a manure pit to unclog a pipe. When he collapsed, a worker tried to rescue him, the farmer’s mother hurried down the ladder to help both of them, and her son died trying to help her: a chain of death involving 4 people. And a team of pathologists working in a poorly ventilated autopsy room were nearly overcome by fumes from the victims’ bodies.

We learn about the virtues of spit, how to survive being swallowed alive, why some animals would die if they didn’t eat their own feces, how competitive eaters train, the mechanics of transporting contraband in swallowed packets or by rectal insertion, flatulence research (one curious finding: men fart more, but women’s farts smell worse), why the stomach doesn’t digest itself (actually, it does, but the stomach lining constantly renews itself), why increasing fiber in the diet might be bad for you, the role of chronic constipation and megacolon in Elvis’ death, and how surgeons attempted to cure diarrhea by excising a section of bowel and re-installing it backwards to achieve reverse peristalsis (this didn’t work).

If you read this book, you will be amused and will learn many things, although some of them might not make for suitable dinner conversation.



Posted in: Basic Science, Book & movie reviews, History

Leave a Comment (22) ↓

22 thoughts on “Adventures on the Alimentary Canal

  1. Narad says:

    the role of chronic constipation and megacolon in Elvis’ death

    Hmph. And now I’m familiar with the Bristol stool chart.

  2. elburto says:

    Oh Narad, you’ve never seen it? The other Mrs elburto had a delightful stay on a gastro ward, and had to chart everything that left her outbot, so to speak

  3. goodnightirene says:

    I’m going to get the book just to see where the fart studies were done. I’m pretty sure his smell worse, but in fairness I want to know the criteria used to evaluate fart potency. :-)

  4. Mika says:

    Just to let you know that the Spine Blog recently had a piece about new acupuncture study, in case anybody’s interested in tackling the subject:

  5. Jacob V says:

    I’m pretty sure it was when Megacolon switched from Marvel to DC is that he really started causing problems.

  6. annappaa says:

    men fart more, but women’s farts smell worse

    I, too, must admit to some skepticism there. I’ll have to find the book to track down that study, but my spidey sense is telling me that it must have been a very small study!

  7. Harriet Hall says:

    I’m skeptical too; don’t think the findings have been replicated. The book also reports that our own farts don’t smell as bad to us as they do to others.

  8. FulfilledDeer says:

    “The book also reports that our own farts don’t smell as bad to us as they do to others.”

    That however, is a fact. A law of the universe. Constant. When things seems to be falling apart all around me, I take solace that my own brand is most comfortable to me.

  9. FastBuckArtist says:

    Women eat more sugary foods containing polysaccharides and oligosaccharides, these complex sugars go down the intestine and feed bacterial activity, producing foul smelling blasts of sulphur compounds. Wouldnt stay downwind from that.

  10. kathy says:

    Aha! For every set of facts there may be several explanations … FBA reckons it’s what women eat, but how about this one: due to societal pressure, women hold back their parps till they can hold back no more, then let loose. The extra time inside allows more and different gases to join the exodus.

    OK, it’s as full of holes as a colander, but This Is My Theory, as Ann Elk said about the Dinosaur.

    Any more Theories out there?

  11. elburto says:

    @Kathy – When I volunteered. on a sexual health service website I was stunned at how many straight women admitted to holding in farts, or even bowel movements, from their husbands/boyfriends.

    One woman went on a two week holiday with her boyfriend and took the max amount of loperamide every day so that he wouldn’t realise she had a functioning gut. The sheer amount of women who admitted doing the same was tragic.

    There were married/cohabiting women who’d been with their male partner for 5/10/15+ years and never passed wind in front of them, or defecated while they were in the house together. I was half appalled/half sad.

    I singled out women with male partners because the women with female partners didn’t care about their bodily functions. Presumably because they know other women do it. Hell, my partner and I both have IBD, so there’s usually no choice or ability to hold back, unless we want to explode!

    So maybe your theory about holding it in is right.

  12. Narad says:

    One woman went on a two week holiday with her boyfriend and took the max amount of loperamide every day so that he wouldn’t realise she had a functioning gut.

    Hell, I’ve done that just by sheer willpower. I had a roommate one summer who went three weeks. Neurosis can be strong stuff.

  13. kathy says:

    Oh wow @elburto! … I didn’t mean this seriously, not at all. It was just a half-joking attempt to broaden the number of possible explanations, and maybe have some fun with alternative (equally wacky!) theories about Why Women Fart Less but Smellier than Men.

    There must surely be some more options? This strikes me as an amusing and actually quite useful exercise. Maybe I’ll try it out on my Honours class next week.

  14. mousethatroared says:

    @ Kathy – if I had to make a guess, it would be hormonal differences. Just because I’m into blaming hormones for everything in my life right now. :)

  15. BrewandFerment says:

    Naval Aviator I know made a deployment bet that he could go the longest of his squadron without taking a dump…and then there was the lactose-intolerant executive officer who was banned from the bridge after he’d eaten ice cream. The things ya do to liven up the dull parts at sea.

  16. Bitter Vetch says:

    The section of the book regarding farts has been excerpted on Salon. Interesting reading:

  17. kathy says:

    @mouse wrote “if I had to make a guess, it would be hormonal differences. Just because I’m into blaming hormones for everything in my life right now.

    Mouse, I’d like to name a new Fallacy, using your data as a fine example thereof … the Nearest Pole Fallacy. Because as we all know, the nearest telephone pole always is/looks the largest. Thanks you for your contribution to my mental armory {K. looks solemn as a funeral}{then grins}{and winks}.

  18. mousethatroared says:

    Kathy, I would be offended that you think my “brilliant” guess is based on a fallacy – But that’s a damn good illustration of my fallacy, so I feel honored instead.

  19. kathy says:

    G’wan @mouse, you knew it was fallacious and I knew you knew it. So we both knew. I’m glad you aren’t offended … presumably the hormones are behaving themselves today {ducks hastily below the parapet, peers anxiously over with one eye … is it safe to come out yet?}.

  20. mousethatroared says:

    Oh, yes. Mock offended is hard to communicate in type. Maybe I should have added a winky face.

    Funny, though, having posted my guess, I found I started feeling rather committed to it. I even came up with a whole rational for why hormones could cause GI differences and thus flatulence differences in the sexes. Not to mention that it is a guess that is vague enough to encompass a very broad range of answers. Is there any human function that doesn’t have some connection to some hormone?

    So sort of a shot gun fallacy (does being vague qualify as a fallacy) as well as a nearest pole fallacy.

  21. elburto says:

    @BandF – When my uncle was on certain high-risk tours of duty, mainly Croatia and the first Gulf War, he (along with the rest of his regiment) was given industrial strength gutstoppers.

    When he returned to the garrison (after his tour) he would lock himself in the bathroom (location of the only toilet in that house) with drinks, snacks, and a stack of reading material.

    The first time this happened my aunt stuck around.

    Every time after that she packed up their three kids and headed north to stay with my grandparents for a week. Apparently the smell had been so bad that first time that she thought she was going to have to redecorate!

  22. elburto says:

    I’m halfway through ‘Gulp’, it’s fabulous. I recommend it, from the bottom of my intestinal tract!

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