Recently, a friend related a humiliating anecdote: he had been having digestive problems, and his gastroenterologist requested detailed reports about his bowel movements. Instructed not to be squeamish about painting an accurate picture, he composed a long missive about the consistency, color, and frequency of his eliminations — only to realize that he had sent the email to his employer, instead of his doctor. He apologized profusely, and received a confused but sympathetic reply assuring him that digestive issues are “very common” these days. They are indeed: today, anywhere from 25 to 45 million people in the United States complain of digestive upset. The stifled Victorians had their hypochondriasis and “change of air” cures, the 1960s housewife her migraines and her melancholia, and today, Americans of all stripes seem to be experiencing a crisis of digestion. Is the precipitous rise in digestive disturbances the result of decades of SAD (the Standard American Diet), a physiological reaction to end-of-empire excess, or perhaps the vocalization of a long-hushed “female complaint” freed by changing social mores to come out of the woodwork? Whatever it is, it’s usually diagnosed as irritable bowel syndrome, or IBS. 

It has a name, but not much else. IBS is a so-called “functional disorder,” meaning that it is a condition without identifiable cause. Unlike with inflammatory bowel diseases such as Crohn’s or ulcerative colitis, patients diagnosed with IBS have no medically detectable signs of damage or disease in their digestive tracts. Essentially, IBS is diagnosed when tests come back normal; it’s what’s written down on a chart when there’s nothing else left to identify. Many people with IBS struggle with the implication that their symptoms are made up — especially as IBS both relies on self-reporting and presents differently from patient to patient. It is a catch-all term for a variety of gastrointestinal ailments, including cramping, bloating, intestinal gas, diarrhea, and constipation. Statistically, it affects more women than men, and is most common in people under 50. Regular exercise, cognitive behavioral therapy, yoga, and meditation have all been shown to alleviate symptoms. Even so, “IBS is not a psychiatric illness,” says Dr. Arun Swaminath, director of the inflammatory bowel disease program at Lenox Hill Hospital in New York City, “though stress and depression can make symptoms worse.” Despite its growing prevalence — IBS is the most frequently diagnosed gastrointestinal disorder — some doctors and digestive specialists question its utility as a medical construct, since the diagnosis does not elucidate anything about patients’ physiology or the causes of their discomfort. It is, however, very profitable: in the United States, the annual medical costs associated with IBS exceed $1 billion. 

Despite the heretofore unmentionable symptoms of IBS, the disorder has also accrued a certain cultural capital. Membership in what the writer Charlotte Shane describes in The Cut as “the IBS-hot-girl legion” seems to have become legion indeed. An Insider article notes that “all hot girls constantly fart, burp, bloat, and suffer from constipation and diarrhea,” at least according to TikTok, where videos with the hashtag “#hotgirlswithIBS” have received 11.9 million views. It’s a popular topic among influencers like Emma Chamberlain and Claudia Kathryn, who recognize the wellness marketing value of what Katie Kane has called “bloating positivity” and have done much to make diarrhea and intestinal gas hallmarks of modern femininity. (Of course, toilet humor has been popular since the beginning of shared human society — the earliest written joke in all of history is about a young woman farting in her husband’s lap, from Sumeria, 1900 B.C.) Brands have been quick to capitalize on the trend: you can purchase any number of IBS-themed sweatshirts promising to “celebrate” the female body’s “natural functions,” or emblazoned with “Hot Girls Have IBS”; the same phrase adorned a billboard in Times Square this spring. However, though Hot Girls™ may be the most vocal sufferers, they aren’t the only ones. Teenage girls and young women, with their finely tuned sense of the zeitgeist, might simply be speaking to a larger societal shift. The question is, what’s coming? 

The “hot girls have IBS” trend began in the spring of 2021, but that wasn’t the first time that digestive issues have been au courant. In “The Grand Organ of Sympathy”: “Fashionable” Stomach Complaints and the Mind in Britain, 1700-1850, medical historians James Kennaway and Jonathan Andrews demonstrate that in Georgian Britain, digestive upset was considered quite debonair, so much so that it was linked to “lifestyle and virtue” (at least, as long as it did not “present dramatically unsightly symptoms”). Although letters, journals, and medical records indicate that stomach ailments crossed class lines, “associations between excessive consumption and elite status lent a touch of glamour to digestive problems.” Moreover, “the context of ‘fashionable disease’ that linked medical conditions to status, wealth and sensitivity set the scene for cases of sufferers who were able to ‘enjoy’ or make a virtue of their symptoms.” Then as now, the condition’s chic veneer coincided with accusations that its symptoms were fake, exaggerated, or a matter of hypochondria. A 1737 satirical article from The Gentleman’s Magazine, for example, suggested why well-to-do “Ladies” complained of stomach problems: “its Diagnosticks are neither visible nor certain, it is pleadable against husbands, neighbours and Relations, without any possibility of being traversed.” 

Almost a century later, digestive infirmity remained every bit as popular. In 1829, William Wadd, surgeon extraordinary to George IV, groused that fashionable ailments of the stomach accounted for “one-half the complaints of mankind.” Despite the air of fraudulence hanging about the stomach malady, it remained fashionable thanks to associations with refinement, “intellectual superiority,” and “poetic feeling,” per Kennaway and Andrews. Physician-poet Richard Blackmore’s 1726 Treatise of the Spleen, for example, posits that those suffering digestive problems “excel their Neighbours in Cogitation and all intellectual Endowments” because their digestive “juices” retain acidity and thus stimulate “animal spirits” to yield “a greater Plenty of clear, surprizing, and beautiful Ideas.” Medical theories also ran in the opposite causal direction, with doctors arguing that the nervous strain of intellectual life was great enough to disturb the entire digestive system. In 1800, Thomas Trotter, a leading medical reformer in the Royal Navy, asserted that “Intense thought” could so affect the harmony of the stomach as to “reduce the philosopher to an idiot.” 

By Trotter’s time, the digestive tract’s special connection to the nervous system had been somewhat well established. The stomach, he wrote, being “endued by nature, with the most complex properties of any in the body,” formed a “centre of sympathy between our corporeal and mental parts, of more exquisite qualifications than even the brain itself.” In accordance with its purported relationship to genius, the stomach thus came to be viewed as an organ of perception, one that could react to and bear the traces of contemporary events. At the turn of the nineteenth century, Lady Louisa Stuart blamed her father’s poor digestion on “the abuse of the newspapers,” which, she wrote, “print the most impertinent, spiteful things every day.” Meanwhile, James Johnson, a gut specialist and contemporary of Lady Stuart’s, attributed his patients’ stomach troubles to the rapid changes wrought by capitalist development in the early nineteenth century; the steady growth in digestive ailments, he maintained, was a result of “speculative risks” that disturbed “the functions of the digestive organs.” 

With the onset of the 1830s cholera epidemic, the non-fatal digestive condition fell dramatically out of vogue. Still, the Georgian-era insight into the connection between the stomach and the psyche proved to be of some lasting scientific merit. The National Institutes of Health’s Human Microbiome Project, the European Commission’s MetaHIT project, and the University of California, San Diego School of Medicine’s American Gut Project, among others, have illuminated the complexity of the “gut-microbiota-brain axis” (sometimes more simply called the “gut-brain axis”), a system of pathways linking the nervous system and the microbial life of the gastrointestinal tract. “Microbiota” refers to the microbe population in a specific ecosystem of the body, such as the dermis or the colon. Among the estimated 10,000 species of microorganisms present in the human body, the gut microbiota comprises the largest and most diverse community, with an average of 400 trillion microbes living in this region alone. 

This discovery was made possible only in the last century, with the introduction of new genetic sequencing technology, though microbiological research began when the first sophisticated microscopes were developed in the 1600s. In the latter part of the 1800s, German physician Robert Koch’s discovery of microbial infection and its relationship to pathogens gave microorganisms a bad name as agents of disease for nearly a hundred years. New genetic research tools, introduced later in the twentieth century, have since proven the complexity and ubiquity of the microorganisms that have coevolved with us, among which are not only viruses and bacteriophages, but also fungi, algae, innocuous bacteria, single-celled animals called protozoa, and other forms of microbial life that play critical roles in human health. In the history of science, then, microbiology is still a very new discipline; the first working definition of the “microbiome” didn’t emerge until 1988. Referring not only to the resident microorganisms but also to their “theatre of activity,” the pioneering article’s description outlines “a characteristic microbial community occupying a reasonably well-defined habitat which has distinct physio-chemical properties.” Only in 2020 would this definition be both accepted and expanded by an international panel of scientists seeking to emphasize the microbiome’s “dynamic and interactive micro-ecosystem.” Likewise, broader scientific interest in the gut-microbiota-brain axis developed as recently as 2004, when a study found that mice with weak microbiomes exhibited more active stress responses than counterparts with a richer and more diverse gut microbiota. Since then, an explosion of research in this field has shown that through the gut-microbiota-brain axis, the cognitive and emotional centers of the brain communicate intimately with the gastrointestinal tract. 

It turns out that the microbial life residing in the gut is not only crucial for digestion, but for the regulation of brain chemistry and the function of neural systems associated with anxiety and memory function alike — gut bacteria are necessary collaborators in the production of neurotransmitters like dopamine, GABA, and norepinephrine. Researchers estimate that gut bacteria are responsible for producing a staggering 90 percent of serotonin, the neurotransmitter that’s targeted by most antidepressant pharmaceutical therapies. Among IBS patients, depression and anxiety are found at higher rates than in the general population; sufferers also demonstrate an altered microbial synthesis of chemical precursors for neurotransmitters like serotonin. Per the World Journal of Gastroenterology, “it has been reliably demonstrated that manipulation of the microbiota can influence the key symptoms, including abdominal pain and bowel habit, and other prominent features of IBS,” and that additionally, “there are clear mechanisms through which the microbiota can produce these effects, both humoral and neural.” Robert Burton’s 1621 Anatomy of Melancholy described how disordered digestion can send “windy vapours” to the brain, “which trouble the imagination, and cause fear, sorrow, dullness, heaviness, many terrible conceits and chimeras”; current microbiology indicates that he wasn’t far off. 

The gut-microbiota-brain axis is bidirectional, however, meaning that as much as the microbiota of the gut affects the nervous system, the nervous system can influence the gut microbiota. As noted by the authors of “The Microbiota-Gut-Brain Axis” in the journal Physiological Reviews, “Stress, in particular, can significantly impact the microbiota-gut-brain axis at all stages of life.” In the medical sense, stress is a state in which the homeostasis of an organism is disturbed due to either an actual or perceived threat. The gut microbiota, thanks to the gut-brain axis, is acutely sensitive to psychological as well as physiological stress. As the authors detail, stressors ranging from maternal separation to overcrowding have been “shown to change the composition of the gut microbiota,” which in turn is responsible for producing the neurotransmitters that regulate our nervous systems. To the popular question of whether IBS is all in your head, the answer is yes — once you realize the head is also in the stomach. 

It’s no coincidence that IBS symptoms in individuals are reported to have either worsened during the pandemic, or appeared for the first time, according to studies from both pharmaceutical companies and medical research institutes. The events of the past three years have exacerbated an already poor mental health climate in the United States: though the percentage of adults who report an unmet need for mental health treatment has increased every year since 2011, depression rates have tripled since the early months of 2020. “The sustained and increasing prevalence of elevated depressive symptoms suggests that the burden of the pandemic on mental health has been ongoing — and that it has been unequal,” says Catherine Ettman, a doctoral candidate at Brown University’s School of Public Health. “Low-income populations have been disproportionately affected by the pandemic, and efforts moving forward should keep this population in mind.” Despite the popular association between constipation and high-profile influencers, gastrointestinal maladies like IBS have repeatedly been shown to occur most in low-income populations. As a study from researchers at the University of Sydney concluded in the journal Gut, “low socioeconomic class should be considered a risk factor for both upper and lower gastrointestinal symptoms.”

Another perspective comes from Dr. Rupa Marya and journalist Raj Patel’s 2021 book Inflamed: Deep Medicine and the Anatomy of Injustice. Marya and Patel argue that “most doctors — most humans, really — have unwittingly inherited a colonial worldview that emphasizes individual health, disconnecting illness from its social and historical contexts.” They draw on the medical concept of the “exposome,” or “the sum of lifetime exposures to nongenetic drivers of health and illness from conception to death,” to reflect on the destructive effect of environmental stressors on the human body. In addition to ecological, chemical, and biological elements in the environment, Marya and Patel’s exposome encompasses social, psychological, historical, and political factors that cause significant stress. While Inflamed focuses on the unequal burdens carried within Western healthcare systems and the broad reach of these burdens — there is good evidence that the physiological hallmarks of oppression lead to abnormal organ development, cancer, and disorders such as type 2 diabetes, cardiovascular disease, kidney disease, and osteoporosis — the book pays special attention to the microbiome. Considering the millennia of coevolution between our microbes and ourselves, Marya and Patel conceive of the gut microbiota as a system of relationships that reflect within the body the health of the environment outside it. Though their focus is not on IBS in particular, their expanded definition of the exposome and its impact on the sensitive gut microbiota implicates everything from police violence to the housing market to student loan debt in the digestive crisis afflicting the modern American, in addition to the more classic gut microbiota stressors of, for instance, living in a food desert or consuming produce with pesticide remnants.

To follow the logic of Inflamed, IBS is undetectable within the body because it is a problem of the body’s context. If this is the case, then individualistic treatment approaches will be just as counterproductive for treating IBS as they are for diagnosing it. Consuming more kefir will not sufficiently ameliorate the effects of stagnant wages or housing instability on our microbial communities (though it won’t hurt). The popular approach to IBS, however, usually begins and ends with diet. There are thousands of articles on avoiding “inflammatory” foods and a booming cottage industry of variously “soothing” and/or “gut-activating” nutritional plans. Especially misleading accessories to this approach are “food sensitivity” test kits, which have become widely available for purchase over the counter. But diagnosing food allergies is notoriously difficult; there’s no simple lab study to determine what someone is allergic to. In fact, the gold standard of allergy diagnosis is what’s called a “double-blind oral food challenge,” a clinical exam wherein doctors introduce patients to substances — either placebos or suspected allergens; neither party knows which — to see how they react. 

Not only are at-home food sensitivity kits expensive, ranging from around $80 to $130 each, the results are far from reliable. As Dr. Tamara Duker Freuman, a New York-based dietitian, lays out in a piece for Self, these kits usually test for something called immunoglobulin G (IgG) antibodies, which are essentially chemical memories we may develop after exposure to certain foods. Citing a study from The Journal of Allergy and Clinical Immunology, Freuman explains that the presence of IgG food antibodies is a phenomenon common to “virtually all healthy individuals” and indicates “the development of food desensitization or tolerance” — rather than intolerance. When you measure IgG levels in the blood, what you’re seeing is just the body’s exposure to foods eaten in the past. “In my experience, the results invariably suggest a sensitivity to gluten, dairy, and soy — I can’t remember seeing or being told about results that didn’t,” notes Freuman. What these test kits are effective at is promoting severely limited diets, she says; the “sensitivities” to common dietary staples detected by these kits — one from the Austin-based startup Everlywell, for instance, promises to “Check How Your Body Responds To 96 Common Foods” — often lead people to adopt highly restrictive meal plans. And once it takes hold, the idea of certain foods as IBS triggers can be difficult to uproot: people assume they feel lousy after cutting out a wide swath of their own diet because they haven’t yet eliminated enough foods. Freuman writes, “I’ve watched helplessly as my patient disappears down a rabbit hole of food restriction and avoidance that can, for some people, lead to disordered eating.” 

Although disordered eating is not the same as an eating disorder, it is a symptom of one and sometimes a precursor. Essentially, disordered eating entails regularly engaging in unusual eating patterns, such as skipping meals. Over the course of the pandemic, eating disorders have seen the same precipitous rise as depression and IBS. One contributing factor is a spike in food insecurity over the past two years, which predominantly affects low-income households of color and is a frequent indicator of eating pathologies. In her article “Irritable Bowel Syndrome, Disordered Eating, and Eating Disorders” for the journal Gastroenterology & Hepatology, Dr. Kimberly Harer, a clinical lecturer in the division of gastroenterology at the University of Michigan, cautioned clinicians to beware of how “disordered eating habits shift from being a reasonable response to an underlying gastrointestinal condition to pathologic behaviors that cause physical or psychosocial impairment.” The latter, she argued, could indicate that self-reported IBS symptoms are actually signifiers of full-blown eating disorders. Multiple studies, in fact, have demonstrated the overlap between IBS and eating disorders. IBS symptoms have been observed in a majority of people with anorexia and bulimia; in a study from 2005 by Catherine Boyd, 98 percent of patients admitted to an eating disorder care unit were found to have at least one gastrointestinal disorder as well, IBS by far the most prevalent. It’s not hard to grasp why. The tolls of disordered eating — malnutrition, swings from binging to vomiting, anxiety and obsessive-compulsive behavior — can lead to the kind of digestive and psychological stress that wrecks the microbiota of the gut. In turn, recovery from eating disorders can be delayed by fears of post-meal discomfort. Notably, once eating disorders are treated effectively, reported gastrointestinal symptoms significantly decrease. This is not to say that all IBS patients are secretly harboring eating disorders, but that one can obscure the other.

A prevailing irony of IBS discourse is that the syndrome’s growing visibility is attributed not to its correlation with economic injustice and disordered eating, but to a triumphant wellness rhetoric of “reclaiming” or “normalizing” bowel function — usually that of the female body. Consider this excerpt from Fashion Journal, an Australian lifestyle magazine, which notes that “the significance of women claiming their right to not only poop but to do it loud and proud as a hot girl is monumental,” even “a huge step towards destigmatising digestive issues while simultaneously smashing the patriarchy.” But perhaps the only thing that’s normalized by an embrace of IBS is the average American’s worsening ability to properly metabolize innocuous foods. The IBS “diagnosis” is a designation for a whole constellation of symptoms — symptoms that seem to be spreading and intensifying year by year. As Inflamed author Raj Patel noted in an interview this past February, the functioning of the gut-microbiota-brain axis “is a metabolic dance that is in large part unknown to any kind of Western science, but is being destroyed by the advance of capitalism nonetheless.” 

For an increasingly parasocial, technology-mediated populace, perhaps there’s a vulgar thrill to describing bowel movements in public. Ironically, at this point it’s more sacred than profane, a final frontier of privacy that is being crossed by these intrepid IBS truthers. The cultural rise of IBS also makes sense in the context of wellness and body positivity — it’s no longer kosher to insist that “nothing tastes as good as skinny feels.” Women are supposed to love themselves too much for that. Instead they have to declare that they shit their pants if they eat gluten or dairy, so that abstention from those foods is seen as an act of self-care, and not disordered eating. Instead of choosing not to eat, people with IBS just can’t. 

This isn’t to say that the relationship between IBS and food allergies is fake; in fact, food allergies are on the rise thanks to the weakening of our gut microbiota. And a weak microbiota makes for a poor immune system: the lining of the gut secretes a mucus layer called the mucosal-luminal interface, wherein the densest concentration of immune cells in the entire body communicates with the trillions of microbes inhabiting the gastrointestinal tract. These interactions between microbes and immune cells play a primary role in the process by which the body learns to distinguish potentially harmful pathogens from beneficial microbes. The immune system both protects these organisms and harmonizes them with their surroundings; a lack of exposure to enough benign microbes produces an overactive immune system that attacks what it ought to recognize as harmless, such as the proteins in peanuts or shellfish, and thus a food allergy is born. A recent study in the journal Nature also linked IBS to the immune response, proposing that the syndrome might begin with an infection in the digestive tract. When scientists infected the guts of mice with bacteria, they found that the mice’s immune systems not only attacked the bacteria but also formed antibodies against harmless food proteins that happened to be present at the same time. As Dr. Marc E. Rothenberg noted in The New England Journal of Medicine, preliminary results from a test group of twelve patients with IBS indicated that the same mechanism may occur in humans, generating a kind of allergic reaction localized exclusively to the gut. Usually, the immune response launched by food allergies manifests not only in the stomach, but also as hives and, in severe cases, as anaphylaxis. Theoretically, however, the IBS patient’s food allergy may have developed in adult life after a stomach infection, which similarly could have catalyzed the immune system to create antibodies to proteins in previously innocuous foods ingested around the time of the infection. The latest research, Rothenberg explains, suggests that “common gastrointestinal ailments, such as IBS and functional abdominal pain, may instead be food-induced allergic disorders.”

In a New York Times article from December 2021 titled “Are My Stomach Problems Really All In My Head?”, Constance Sommer writes about her struggle to find a successful treatment for her IBS and the validation she found in Rothenberg’s study: “Now this research seemed to indicate what I was feeling could be an allergic reaction — one no amount of hypnotherapy or journaling was going to make disappear.” She adds, “I’ve finally come to the conclusion that suits me: my gut is different than other people’s.” The irony, of course, is that her stomach problems are the same as those of the 25 to 45 million other Americans with IBS, and that number will only increase if the findings from Rothenberg’s study on the development of IBS hold, as these kinds of localized allergic responses to food will continue to proliferate. A healthy gut microbiota plays a crucial role in separating out the kind of toxins that lead to a stomach infection in the first place; the weaker it is, the more hostile — and less discerning — the immune system becomes. Rothenberg notes that his discoveries hint at “new possibilities for the treatment of irritable bowel syndrome and related abdominal pain disorders,” such as high doses of antihistamines and targeted elimination of the immune cells responsible for initiating an allergic response in the gut. But digestive antihistamines won’t prevent the stomach’s identification of anodyne proteins as harmful bodies: they’ll be too late for that. The most they can do is provide a path to treatment for this elusive syndrome. In the conclusion of her article, Sommer writes, “if I’m never able to eat another grilled cheese sandwich (dairy cheese, wheat bread, actual butter), I can live with that. And that’s the most relaxing mantra there is.” Perhaps Sommer can manage in a world without the taste of butter, but I would prefer to live deliciously.