Gulp! Author Mary Roach's trip down the alimentary canal

Mary Roach is the author of Gulp: Adventures on the Alimentary Canal.
Mary Roach is the author of Gulp: Adventures on the Alimentary Canal.
Chris Hardy

Whether writing about cadavers, sex or the digestive system, Mary Roach probes the annals of history and science for the funniest anecdotes and most moving characters she can dig up. She assembles these tales into biological travelogues that tour readers through those parts of their bodies that everybody shares and society deems dirty. Roach is a fart humorist and biology writer wrapped up in one package, and her terrific books delight our intellectual curiosity and inner-adolescence alike. In advance of her upcoming readings at the Boulder Bookstore and Tattered Cover, Westword spoke with her about her latest book, Gulp: Adventures on the Alimentary Canal. See also: Bruce Weber on bicycling, mortality and Life Is a Wheel

Westword: Talk about what you are bringing to the Boulder Bookstore and the Tattered Cover. Mary Roach: I'm on the paperback tour for Gulp: Adventures on the Alimentary Canal, which kind of sums up the book. It's an unconventional travelogue through the food chute with various random stops along the way according to what I found interesting, surprising and occasionally gross.

Talk about how you came across this subject, and what it was like to explore this topic.

I come to topics in an inside-out way. I had some material from various assignments over the years that was orphaned. It didn't make it into a story. Right now, I'll look at a cluster of stuff and I'll say, "What would be the umbrella book here?" I had some material, and it occurred to me that the whole alimentary canal was a very Roachable place. I tend to write about the human body and unusual aspects of it, strange contexts and situations it's put in. There wasn't an ah-ha moment or any single inspirational event. It was just musing on a couple chunks of material I wasn't able to use in the original assignments.

Talk about what the alimentary canal is...

The alimentary canal is everything from nose to tail. From the time you put something in your mouth and chew it and experience it all the way through to the other end. We're kind of doughnuts in a way, and the alimentary canal is a tube all the way through us. It's almost more like the outside of the body, because it's not sterile. It's full of bacteria and unsavory things. The rest of the body is secluded and sterile and kept pristine. The alimentary canal is kind of anything goes. It's like an offshore gambling zone. It has its own rules and is smelly and gross and full of bacteria. It's a hole that goes all the way through us. It afforded me a lot of interesting stops along the way. Talk about a few of your favorite stops. We start out in the nose. The nose is a lot more important than most people realize. When you're eating, your experience of flavor is about 80 percent olfactory. All these volatile gasses waft up into the nose, and you experience them as part of the experience of eating. The minority of the experience is the tongue. The tongue is sort of sweet, sour, salty and bitter. It's the shirt and pants. All the lovely accessories are up in the nose.

We've got the mouth, several stomach chapters, the intestines and gas. The stomach was interesting. I spent some time there. One chapter is historical. It has to do with William Beaumont and Alexis St. Martin, who were an odd pair. Beaumont was a physician in the 1800s who treated a guy with a gunshot wound to his side that left an open hole in his stomach. Beaumont was able to observe and look inside his stomach, and he became obsessed with the actions of the gastric juices, because no one really understood how the stomach works or what it does. He kept doing all these observations on Alexis St. Martin, who eventually got fed up and ran off. Beaumont would track him down by sending letters off to fur companies. St. Martin was a fur trapper. For thirty years, the two of them had this strange, mutual dependency. There's a chapter about them.

I have a chapter about competitive eating and how much it takes to burst the human stomach, which is actually surprisingly hard to do because the stomach has a lot of safety mechanisms. If you push it far enough, it will reflexively empty itself. You'll throw up. That's actually a life-saving thing. When stomachs do burst, it is often because of gas. If you've eaten a lot of food and your stomach is full of food and you want to feel better, they take some sort of bicarbonate soda -- some gas-producing thing. Well, the gas can build up so fast that the body can't keep up and the stomach will rupture, so it's typically gas that's ruptured the stomach.

Again, there is this safety mechanism. The technical term is the transient lower sphincter esophageal relaxation, which is a very multisyllabic term for belch. The belch is really just a way to release pressure on the stomach and make it less likely to burst if you're overdoing it with the fizzy stuff. Occasionally, people have eaten sauerkraut or something with a lot of bacteria and fermentation where that's produced gas as well. There are a couple cases of stomach ruptures from that. By and large, it's very hard to burst the stomach unless you're unconscious.

There are a couple of chapters about intestinal gas and the challenges of researching it and collecting it and studying it. It has been done the way you think it would be, by putting a tube up someone's butt, but that's a very uncomfortable thing, and it's very difficult to get people to agree to walk around with a tube up their asses. That's only been done once. It was done by a researcher named Colin Leakey, which I thought was astoundingly appropriate. It may be pronounced "Call-en," but I choose to say Colon, like Colin Powell, because it makes the joke better.

Colin Leakey was the only one who did it that way, as far as I know. There is a researcher named Michael Levitt who did it in a very simple way. He just gave people a piece of paper and a pencil. Every time they passed gas, they'd make a little mark. That is not the best way to do it, because if you're someone who is sort of dainty and holds it in and lets it out in quiet and unobtrusive ways, the same volume of gas may wind up with ten little hash-marks, whereas if you're somebody who just blows it out in one blast, you'll have one mark on your report. It's not particularly accurate. Anyway, there's some material about the challenges of studying intestinal gas.

Then we have a rectum chapter. The rectum is a storage facility, one that we are very lucky to have, because it means that we don't have to immediately go and empty things that show up at the gate. We can hold onto them for awhile. In order to study that, I made a trip down to a Avenel State Prison, where there are individuals who smuggle things in and out using their rectums -- using the rectum for the purpose for which it evolved, for storing things like a handy pocket. That chapter has to do with the defecatory reflex and the manual override of that reflex and how long you can do that and the troubles that sometimes result. That was an interesting attribute. The folks call it hooping. Those are some highlights. Read on for more from Mary Roach.


Gulp! Author Mary Roach's trip down the alimentary canal

You're often dealing with these intensely visceral, bodily subjects. Has that always been a fascination? How did you stumble into that? I think it's more that I'm interested in the stuff that everyone's interested in, until they learn that they're not supposed to be interested in it, which I think explains the success of my books -- however successful they are. It isn't so much that I have a unique interest in this stuff. I think that everybody has a closet interest in this stuff. I can't point to anything in my formative years that would make me curious about these things. When I was writing for magazines, I didn't really cover this. I wrote for a magazine called Hippocrates, which later became Inhealth. It used to be a good magazine, and a lot of the reporting had to do with the human body and health. That was a beat that I fell into and that I found interesting. I guess if I had to point to something that pushed me off in this direction, I guess that would be it.

Talk about your strategy with humor and making these biological and scientific topics accessible.

It's very much what I do as a part of the research and reporting as much as or more than the writing. I'm a massive filtration device. I'm going through lots and lots of materials and archives and PubMed, and I'm picking people's brains as a way of looking for astounding, strange, fascinating, surprising material. Once you find something like that, once you find some of this material, it kind of writes itself. It's not very hard to make it entertaining and surprising and funny. It's very much material dependent. If you sat me down and handed me a random journal article or topic and said make this funny, I don't know if I could. There are definitely parts of my books and magazine assignments where humor isn't appropriate, and it would be hard to do, and I wouldn't even attempt it. It's me scouting around looking for material that lends itself to that treatment.

As you tour this book and have conversations with the public, have there been any surprises that have occurred on the speaking route?

I'm always surprised by the creativity people apply to their questions. For example, the other night, a man raised his hand and said, "You know with hot stuff and chili peppers, you build up a tolerance and you are in fact killing off pain receptors in the mouth." He said, "Why is it that you don't build up a tolerance on the other end?" I thought that was a really great question. I get a lot of wonderful questions, and the Q&As are always really entertaining. If I could, I would just skip to the Q&A. I always urge people to feel free to ask anything at all. This is fun for everyone in the audience, too. I might not have an answer, but it certainly is fun to try.

Was there an answer to that question?

The answer was, "I don't know! I don't know why. Perhaps we do build it up, but it certainly doesn't seem like it." It's a really great question.

Talk about your research process?

The most important thing early on is to figure out where I'm going to go -- which lab or state prison or archive or whatever it is that's going to become the narrative setting for the chapter. It's not enough for me to give people facts and information, as interesting as it may be. I want them to be in the setting of people doing things and talking, so there's characters and dialogue and a bit of narrative in each chapter. Sometimes it's an historical narrative. That's the hardest thing.

I spend a lot of time pestering people by email and phone and picking peoples brains and saying, "What do you have coming up?" or "I read about something you did in the past. Will you be following up with any related work?" or "What have you got going?" I have to be very direct. It needs to be something I can see and something I can visit. I'm not looking just for what papers you have published. It's very much trying to schedule something where I can go and be there for a couple of days. That takes up a lot of time, and once that's in place, it's really just a matter of following through, going there and doing the writing.

Roach will read from and sign copies of Gulp at 7:30 p.m. Tuesday, April 22, at the Boulder Book Store, 1107 Pearl Street in Boulder, and at 7:30 p.m. Wednesday, April 23 at the Tattered Cover, 2526 East Colfax Avenue. For more information, call 303-477-2074 or go to

Follow me on Twitter: @kyle_a_harris

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