The Rise of Smart Toilets: Wellness Trackers for Gut Health

It was only a matter of time before wellness trackers—already out there trying to optimize our heart rate, sleep, stress, steps, blood sugar, and menstruation—came for perhaps the most private biosignal of all: our poop.

The global gut health market is expected to reach nearly $106 billion by 2029, and a handful of companies are betting they can use stool data to provide in-depth health insights, nudge people to change their diets or lifestyles, and advise them to see a doctor if their bathroom habits seem amiss. But gastroenterologists are skeptical that products that rely on AI to analyze images of what’s going on in your toilet bowl are worth the price just yet, and data-privacy advocates warn that people can get locked into long-term subscriptions just to access their own health data.

Among the companies touting smart toilets are Kohler Health—an offshoot of the eponymous plumbing giant that sells its device for $449 plus $130 for an annual family membership—and Throne, a startup that raised $10 million in July. Its product is $399 plus $70 for an annual membership.

Both companies’ stool trackers are sleek white devices that clip to the toilet and have cameras facing down into the bowl. (They are adamant that the cameras cannot turn skyward.) When you sit down, the device uses a light sensor to record a video of your deposits, then feeds them into an algorithm that analyzes your urine and stool consistency and color, as well as other metrics. A few minutes later, you get your bathroom-break report card care of an AI-powered app that tracks gut health and hydration scores.

The companies say they are taking a completely different approach from at-home gut microbiome test kits. Those kits, which claim they can use stool samples to identify food sensitivities, provide dietary guidance, and more, come with thin to nonexistent evidence of their efficacy. The new stool trackers aim to identify what's normal for an individual rather than issuing a binary healthy-or-not verdict.

“This is all deeply personal and very individual—digestive patterns are very different,” says Nora Tophof, Kohler Health’s managing director.

Even so, for healthy people with regular bowel movements, stool trackers may not offer much in the way of new insights, says Daniel Freedberg, a gastroenterologist in New York and a spokesperson for the American Gastroenterological Association.

“It kind of seems like overkill,” he says. “If you want to look at your stool, you can just look at it yourself. I don't know that the AI is bringing a lot of new science to this.”

Tophof says that for healthy people, the real value comes from long-term tracking to identify patterns they can act on—for example, if they realize they’re always dehydrated over the weekend or that a particular food or medication tends to upset their stomach.

Scott Hickle, Throne’s cofounder and chief executive officer, says people with inflammatory bowel disease or other digestive conditions can benefit from regular, automated stool monitoring. “Their physicians ask them to track, or keep stool logs … and compliance for that is basically zero,” he says. “No one wants to journal about their poop.”

Throne plans to offer more than helping users track their gut health. Rates of colorectal cancer have risen among younger adults over the past decade, and it is now the leading cause of cancer death among those under 50. Doctors don’t quite know why, but exposure to ultra-processed foods, microplastics, and antibiotics are prime suspects. Screening for colon cancer typically involves a colonoscopy—or a stool-based test that looks for hidden blood in feces.

Hickle says the next generation of Throne’s device will be capable of detecting blood in fecal matter using multispectral imaging that is much more sensitive than the naked eye. Early tests with a prototype are promising, he says, and the updated device could launch within two years. The company has yet to determine a price, but Hickle says Throne's goal is “to make it as accessible as possible so that this can benefit as many people as possible.” He hopes that blood-based data will eventually help detect colorectal cancer, though it’s not clear whether this approach would be as good as testing in medical labs.

“We don't want to be in the business of making diagnoses,” Hickle says. “Looking for those patterns of bleeding over the course of weeks and months should be enough to get someone to at least escalate the conversation they have with their physician.”

Kohler Health says its tracker already alerts users when it detects blood in the toilet. While often harmless—common examples include menstrual blood and hemorrhoids—it can also be a sign of serious health conditions.

“We really want to help people and ultimately save lives,” Tophof says.

Even if the trackers’ blood-detection technology bears out as a clinically meaningful signal, they are still too expensive to be widely used as screening tools for cancer or other health risks, says Gianluca Ianiro, an assistant professor of gastroenterology at the Catholic University of Rome.

“A screening test should be non-invasive but also cheap—and this is not cheap,” Ianiro says.

Would-be buyers should also consider how much personal data they’re willing to give up for what they get out of using the device—especially because “you’re having to pay time and time again in order to access and analyze your own information,” says Lauren Hendry Parsons, a digital rights advocate at the Mozilla Foundation. If customers keep re-upping their subscriptions, “it may feel harder to detach yourself if you've got years and years of data and information about yourself inside that particular service,” she adds.

In addition to the contents of your toilet bowl—and any details you tell the app about your health, such as diet or medication—Throne and Kohler Health both collect the usual litany of personal data, including name and demographics. Kohler Health also tracks your precise location, while Throne does not.

Both companies say they don’t share user health information for targeted advertising purposes, but they can still share this data with law enforcement, another company in a merger or sale, and third-party service providers for things like IT, customer service, and engagement, according to their privacy policies.

Tophof says Kohler Health doesn’t plan to sell users’ health data. Throne also says it will never do so without express permission. Eventually, Hickle wants to share user health data with universities doing gut health research—but people will have to opt in, and refusing will not affect their ability to use the app or device, he says.

Hendry Parsons has advice for privacy-minded buyers: “Be informed. Know what the trade-offs are, know what you're sharing, know what your data is being used for, and weigh that up against the benefit that you are deriving from the product.”

That calculus might be different for someone “suffering from Crohn’s disease, and this is something which will materially improve your day-to-day life,” she says, compared with a “health optimizer who's casually thinking it might be fun to understand the impact of your homemade kombucha.”