I recently wrote about a hospital system in Colorado that had discovered a way to cross market its more profitable emergency room services if a patient first came to its urgent care center. Pretty clever! Then recently I came across another health care marketing trick close to home and just as sly. As I sat on a New York subway one sizzler of a day, an ad for an ice cream cone grabbed my attention. Ice cream! Hot day! After a closer read, I realized the ad was not touting ice cream but the Center for Advanced Digestive Care, a part of New York Presbyterian, one of the city’s most prestigious hospitals and well known for its TV ads designed to cultivate brand recognition.

Digestive care? Why not? Health care advertising has long bombarded consumers — care for pimples, care for weak ankles, braces for crooked teeth and those gross “pouring on the pounds” warnings from the Department of Health about drinking too much soda. Still, marketing excellence in digestive care isn’t something that would catch the eye of most casual subway riders. The ice cream cone was an effective attention-grabber.

So was the message: “Are her tummy aches too much chocolate swirl or is it lactose intolerance?” Was New York Presbyterian borrowing a page from drug makers? Pharma advertisements are renowned for suggesting that you might have an undiagnosed or untreated disease and then offering remedies to cure it. Consider the ads for the top three most commonly prescribed drugs in the U.S. — Abilify, Nexium (the Purple Pill) and Humira — accounting for over $19 billion in sales from 2013 to 2014, usually featuring people dancing, jogging, and laughing while suggesting that you “ask your doctor” about taking them for depression, heartburn and aches.

I was reminded of the classic book Selling Sickness by Australian health journalist Ray Moynihan and Canadian pharmaceutical researcher Alan Cassels. They shared a number of case studies illustrating drug company strategies aimed at changing the way people think about common ailments and turning natural processes into “treatable” medical conditions. An entire chapter was devoted to menopause.

I knew some people were lactose intolerant and couldn’t drink milk or eat ice cream, but how many? It turns out, according to Medline Plus, a service of the National Library of Medicine, the “condition is normal among adults with Asian, African or Native American heritage. It is less common in people of northern or western European backgrounds.” And just how serious or dangerous is lactose intolerance? Was New York Presbyterian trying to medicalize a rather normal condition? Or was it trying to woo people to its Center to check for other digestive disorders? In the hospital business, more patients equal more revenue, and that’s the name of the game.

The subway ad directed potential patients to a phone number and website, which I checked out. It promoted its various centers of excellence in gastrointestinal diseases, showed a picture of a state-of-the-art medical imaging system and noted that the Center represents one of the first top-tier digestive programs in the U.S. for implementing a patient-centered care model. Who wouldn’t want to call for an appointment to see about their tummy ache?

The ad did say “our care is advanced whatever the condition may be.” But do all patients with tummy aches need advanced care? And isn’t that what a primary care doc is supposed to help patients decide? Shouldn’t patients be discussing their symptoms and concerns with their doctor instead of self-referring to an expensive hospital that must recoup its investment for that super-duper machine it’s showing off?

Geez, I thought going to your primary care doc and starting off in your medical home was what patients were supposed to do now that nearly everyone has insurance. Advertising the latest trendy symptoms and diagnostic technology circumvents a cornerstone of health care reform and stimulates unwarranted demand for services. Those ads may be good medicine for the hospital; but they may not be good for patients or the health care system as a whole. That may not matter in the growing medical marketplace.

Trudy Lieberman is a journalist and an adjunct associate professor of public health, Hunter College, New York, NY. She blogs on the Prepared Patient blog.