This is an archived article that was published on sltrib.com in 2014, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

The digestive tract doesn't sound like best-seller material — unless you're as funny as science writer Mary Roach.

"The pie hole and the feed chute are mine," she writes in her latest book, "Gulp: Adventures on the Alimentary Canal," in which she underwent a sedation-free colonoscopy to view her innards.

Roach's fans expect her to take them along for the ride as she researches complex ideas, always with a light touch. Her books have won awards and a wide readership, ranging from 2003's "Stiff" (about human cadavers) to 2005's "Spook" (researching the afterlife), and from 2008's "Bonk" (science and sex) to 2010's "Packing for Mars" (space). Across all of her books and magazine articles, the writer offers a conversational tone and a saucy curiosity.

She will tell stories of the pie hole and feed chute at a reading on Monday, April 21, at the Salt Lake Public Library.

Subject aside, Roach seeks to explore topics that blend history, humor and science while explaining the human body. And she's always looking for that right touch of "something gross," as she once told an NPR reviewer.

After discussing astronauts' digestive issues in "Packing for Mars," she explores that "something gross" with great relish and even greater detail in "Gulp," a book about chewing, spit, flatulence and excrement. In a review, The New York Times' Janet Maslin called it Roach's funniest and most relevant book, in the way it marries the writer's love for weird science to a topic of everyday relevance.

In an email interview, The Tribune asked Roach about that colonoscopy, researching the chapter on flatulence and the concept of "blaming the dog."

What inspired you to think there would be a book in the digestive tract?

In "Packing for Mars," I came across a study where there were a bunch of space researchers trying to see if man could survive on meals of dead bacteria. That made me think that the science behind eating would be as interesting as the food itself.

What chapter was the most fun to write?

The flatulence chapter was the most fun to write because there is a tremendous wealth of funny material. There is a lot of surprising creativity that went into the study of flatulence. How do you trap the gas? One answer to that is Mylar flatus-trapping pantaloons. There was a guy who studied flatulence in the 1960s whose name was Colin Leakey.

About that chapter, in which you introduce the concept of "blaming the dog": What did you learn from researchers who study flatulence?

People would be surprised to know that most of the gas produced, hydrogen and methane, has no smell at all. The offending culprits are hydrogen sulfide, which we can smell in 2 parts per million. It's a tiny, tiny portion of the gas that is produced. Most of it is not something you can smell. It is flammable, though, so that's one reason why when you have a colonoscopy they have to "clean you out." There have been cases where there have been explosions inside the colon, when there are still pockets of air left in. Not a good thing.

What was the most surprising to you in the reporting?

Reportingwise, I think the rectum chapter, which takes place at Avenal State Prison. [It was] fascinating because I've never spent time in a prison in that setting, so that was a particularly strange and interesting reporting experience. The nose chapter was also surprising in that I did not really appreciate the extent to which we eat with our noses. People tend to think it's all in the mouth, but 80 percent of flavor is olfactory. There is a tremendous contribution made by the human nose.

What was most unusual about your experience viewing your innards while undergoing a "sedation-free colonoscopy"?

While it was occasionally painful, it was manageable pain. It was not nearly as big of a deal as I thought it would be. Really, it's your only opportunity to see the inside of your own colon. While [that] doesn't appeal to everyone, I thought it was pretty special. The colon is surprisingly pink and clean-looking. It's a bubble-gum pink, glistening, tidy place.

facebook.com/ellen.weist —

Food for thought

Mary Roach promotes "Gulp."

When • Monday, April 21, 7 p.m.

Where • Main Library, 200 E. 400 South, Salt Lake City

Admission • Free; for information, call Weller Book Works, a co-sponsor of the reading, at 801-328-2586