Our obsession with digestion—how long it takes, how smoothly it happens, how its byproducts look—is big business. You can find a wide selection of attractively packaged prebiotic, probiotic, postbiotic, and synbiotic foods at any high-end grocery store, and no shortage of gut-health bestsellers at the bookstore or on Amazon. For-profit health companies promise a more “mindful” relationship with one’s digestive tract via stool analysis. Seizing on our need for speed, one such health outfit has now called on people to take the “blue poop challenge,” which measures the amount of time it takes one’s gut to process and excrete a blue dye. Those disappointed with their food-to-poop transit times might look into the personalized diet plans this same company, or countless others, have on offer—for a price.
With this ever-growing market, our guts may seem like trendy territory. But this preoccupation with poop is far from a modern fad. Beneath the cutting-edge technology and flashy packaging, our fascination with digestion is actually very old-fashioned. In 1896, the well-known wellness fanatic and physician John Harvey Kellogg summed up the digestive ethos of his day in a book titled, simply, The Stomach. The highway to health, he wrote, ran through the gut. Indeed, so important was the digestive tract that the body might best be thought of as a “stomach with organs appended.” While we now associate the Kellogg name mainly with the cereal brand he had founded with his brother Will Keith Kellogg, it was not what went into the body that really concerned John Harvey—but rather what came out.
Ideally, that was prolific amounts of poop expelled with great frequency. Kellogg preached to adherents at his then-famous health resort Battle Creek Sanitarium that producing at least three, and much better four, bowel movements a day ought to be the norm. To him, every meal should end with the body dismissing the meal you had two meals ago—expel breakfast after dinner, for example. He considered this a leisurely pace. According to his calculations, this schedule allowed eight hours for food processing in the 25 feet that separated mouth and colon, and a lavish four to six for the remaining 5 feet from colon to toilet.
In his 1918 book The Itinerary of a Breakfast, Kellogg laid out the ideal schedule of arrivals and departures that food traveling through this “subway” might expect, using the metaphor of a commute to describe food moving from mouth to terminus over the course of a single day. His timetable featured the various delays—the wrecks, collisions, and obstructions—that might cause the most dreaded of all ailments in the Kellogg catalog: constipation. Waste that lingered in the body posed a crisis, with halted digestive locomotion supposedly resulting in “putrefaction.” If not quickly emptied, the stomach would pass on its rot to its neighboring organs, resulting in the “autointoxication” or poisoning of the body more generally. (This was a worry that did not easily dissipate. As late as the 1980s, doctors were still disabusing patients of the notion that, as one physician commentator put it, “stools waiting to be expelled” were “evil” objects producing “absorbable poisons.”)
The critical need to keep the digestive system humming along led to the cereal empire associated with the Kellogg name. In the quest for a palatable means to deliver the difficult-to eat fiber needed to keep up this ambitious schedule of production, the Kellogg brothers invented a method for flaking grains. The company’s original flake was made of wheat and called “granose,” but it was Will Keith Kellogg’s marketing of the corn flake that set the Kellogg cereal brand on a course toward greatness.
John Harvey Kellogg’s obsession with digestion was far from fringe in his day. Joining him was a small crowd of gut gurus who each differently parsed what it meant to keep the early 20th-century body—the stomach with appended organs—healthy. Kellogg’s greatest competition was Horace Fletcher, known affectionately to his followers as the “Great Masticator” for his demand that food be chewed to a liquid before being swallowed. In stark contrast to Kellogg, Fletcher dismissed poop as simple waste left over from the production system of the digestive tract. “Digestive ash,” as he politely called it, was not something to “produce.” It was something to reduce, if possible, if one could not eliminate elimination entirely. In Fletcher’s view, the indigestible fiber that Kellogg flogged as the key to digestive health should never go into the mouth in the first place.
Where Kellogg and Fletcher did share common ground, though they probably didn’t realize it, was in their view of the digestive system as just one more of the production systems that had come to typify factories of the day. This was, after all, the heady days of Henry Ford and his assembly line, of efficiency experts Frederick Winslow Taylor and Frank and Lillian Gilbreth, all of whom helped to popularize the ethic—one now embedded in our national psyche—that productivity and speed were the greatest good, and waste of any sort the worst sin. The difference between Fletcher and Kellogg was merely one of perspective. For Kellogg, poop was the system’s product, or at least the guarantor of the smoothly running system. Producing more of it, and speeding up production, was simply good industrial practice. For Fletcher, waste was waste: a sign that the system producing it was inefficient, unproductive, and in dire need of repair. The less of it, the better.
The Kellogg school of thought has had greater staying power. Though some of Kellogg’s more challenging requirements—particularly those having to do with frequency—began to fall away among his heirs in poop-transit theory, self-appointed authorities like the celebrity diet coach Paul Bragg continued to insist upon the potentially poisoning impact of the residual waste that could become “caked on” in the intestine. But Bragg, whose reign as a health guru began in the late 1920s and reached its zenith in the 1970s, was no friend of the enema. Instead, he trained his adherents in the practice of “bowel breathing,” a method designed to force oxygen directly into the bowel by taking a deep breath in and squatting and bearing down as though mid–bowel movement, while slowly exhaling. Through this practice, Bragg promised, you could train your bowels to remove the accreted waste that even the strongest laxatives left behind.
Bragg was also well known for his techniques of fasting, which added what he called “detoxification”—yes, this 21st-century buzzword is actually quite shopworn—to the mix of cures for the potentially poisoned gut. In his 1973 book The Miracle of Fasting, Bragg reported that a 10-day fast he had undertaken in Virginia had produced something remarkable: a turd comprised of a “third of a cup of quicksilver” from a laxative he had taken as a child that had been festering in his gut for the past half-century. This excreted artifact was a revelation for Bragg, who touted it as evidence of both the detoxifying effects of his method of fasting and the dangers of the over-the-counter laxative formulations that competed with his own methods and products.
Even so, the laxative market across the midcentury was already sizable and growing, and whether you were a “Braggart” or not, it was common to view at least two bowel movements a day as healthy. Philosopher Bertrand Russell attributed his own longevity to the two-a-day habit he followed. By 1978, the pharmaceutical company G.D. Searle & Co. announced that in that year Americans had spent nearly $200 million on laxatives.
Though many bought and indeed still buy into the Bragg way of health—his products remain available at your local Whole Foods—his views slowly moved to the fringes of health discourse as time went on. Institutional medicine began to discredit and delegitimatize the several generations of still-popular practitioners and “food faddists,” as they were derisively called, whose views had held such powerful sway over the public. Indeed, as one commentator writing in the late 1970s noted, “the notion that irregularity and poor health are linked has never been substantiated scientifically.” Targeting the gut gurus was also a good way of reducing competition.
Physician advice columnists, a newspaper mainstay in the ’70s and ’80s, began to treat requests for advice about poop frequency with increasing impatience. In response to one anxious inquiry in 1981, the physician Frank Falkner replied, “Your question is like many I receive, so let me deal with this by starting from the beginning.” Dropping the bombshell that constipation had nothing to do with frequency and everything to do with shape and size (constipated stool was “hard, dry and small”), Falkner assured his readers that there was also no such thing as autointoxication. “We really must stop concentrating,” he wrote, “on the importance of the bowels in humans.”
But the frequency of letters like those Falkner responded to (never mind the sheer volume of laxatives Americans were ingesting) express the extent to which Americans—in contrast to the medical community—were not ready to end their obsession with the pace of their bowel movements. The prevailing medical emphasis had moved on to stool composition, with the coprological work of art that is the 1997 Bristol stool form chart, an illustration so captivating that it quickly migrated from the walls of doctor’s offices to adorn mugs, coasters, and plaques. Even still, stool frequency has continued to remain a firm part of the public discourse surrounding digestion, with no end to the steady flow of products that keep the American people’s digestive trains moving along with Kelloggian regularity.
For their part, physician responses to the transit-time question, for at least the past 40 years, have suggested that the individual variability of our pooping habits—which depend on fluctuating factors like hydration, exercise, and how much and what is eaten—mean that the quest for an optimal universal transit time is likely to be futile. That hasn’t dampened our enthusiasm. Laxatives remain big business, of course. But it is the enormous and ever-growing higher-end “digestive wellness” market that has most to gain from the (re)introduction of transit time as a selling point. The grocery-store aisles and “wellness” tests are the product of a more than centurylong war for our guts. The products, testing, and personalized diets it will spawn will undoubtedly be popular. Will any of them make any difference to our health? As Kellogg would see it, the proof is in the pooping.