Guts and Glory: Mary Roach Tackles Digestion

A literary exploration of the digestive process.

Mary Roach tackles digestion in her new book "Gulp."

You must have a pretty high threshold for getting grossed out. But, in writing this book, was there any point where the research made your stomach turn, so to speak? And if so, what did it?

I spent an afternoon in the lab of a saliva researcher in the Netherlands. We collected stimulated saliva— the watery and almost lovely kind you secrete when you chew—and unstimulated saliva, the background kind, thick and ropy. At one point she was talking about the long chains of mucins that make unstimulated saliva so viscous and stringy, and she did a little demonstration for me. That would be the point you're asking about.

As you put it, "The pie hole and the feed chute are mine." You've tackled the taboos that others don't want to touch. Why?

I'm something of a bottom feeder, I guess! I like to cover topics that haven't been covered much, for one thing. I'm drawn to the taboos that surround the human body. I find it fascinating that we are repelled by many of the acts and processes that keep us alive. I think they remind us that we too are, when you get right down to it, organisms: eating, excreting, mating. We don't like to be reminded of what we have in common with animals, I suppose. But all of these processes are miraculous in their way, and worth appreciating and exploring.

[See Toilets With Sex Appeal.]

What are some of the most common questions you get about your book? Is there something everyone wants to know about digestion?

People are very curious about fecal transplants, which I write about, and gastric reflux, which I don't write about. My book is a quirky journey down the healthy alimentary canal, nose to tail. It's not "Dr. Jensen's Guide to Better Bowel Care." But folks don't know that, and often I am asked about medical issues. Just today, in a call-in radio show, I was asked about: canker sores, mucoid plaques and gustatory hallucinations.

[See Top Doctors: Gastroenterology.]

U.S. News is built on the philosophy of providing readers with "news you can use." What practical tips can we take away from your latest book?

Use your internal nostrils! Always go when the urge arrives! Don't give round candies or grapes to toddlers! (Young kids with "immature swallowing coordination" are more prone to inhaling foods. Round items match the shape of the windpipe and completely block it. One doctor I spoke to called sliced hot dogs a "public health hazard.")

[See 6 Dangerous Games Your Kids Should Avoid.]

You've investigated the science of sex, death, outer space, the afterlife and digestion. What's next for you? Is there a topic you refuse to cover?

I don't have a new book underway quite yet. Send ideas! Having covered cadavers and sex labs and rectal smuggling, I would say I'm game to go pretty much anywhere.