A leading gastroenterologist breaks down the most stubborn digestive health misconceptions—and what science actually says
The Gut Health Misinformation Problem
Every scroll through social media seems to surface a new digestive cure—lemon water cleanses, fiber overloads, probiotic miracles. Americans are drowning in wellness advice, most of it unverified. Meanwhile, the real threats to digestive health are quietly escalating. Colon cancer rates have been climbing steadily among people under 55, making it the leading cause of cancer death in that age group—a trend researchers suspect is tied to environment and lifestyle, though the exact causes remain under investigation.
To cut through the noise during Colon Cancer Awareness Month, Dr. Roshini Rajapaksa, a gastroenterologist at NYU Langone Health, laid out the most persistent digestive myths she wants patients to abandon—and what to do instead.
Myth No. 1: Lemon Water “Detoxes” Your Stomach
The warm lemon water ritual beloved by wellness influencers does not detoxify the body. That duty belongs entirely to the liver and kidneys, which filter waste continuously and need no morning citrus assist. What lemon water may actually do is mildly support digestion—its acidity can stimulate bile and gastric juices, and the water itself contributes to hydration. Heating it, however, adds no measurable benefit. If it feels soothing, there is no harm in it, but the detox claim is fiction.
Myth No. 2: You Can Never Have Too Much Fiber
Fiber is essential, but more is not always better—especially when consumption increases too fast. A sudden spike in fiber intake can cause significant bloating and gastrointestinal pain. Worse, fiber consumed without adequate water can congeal in the gut and cause constipation rather than relieve it. The recommended daily target is 25 to 30 grams, and the smartest approach is a gradual increase of roughly five additional grams per week until that goal is reached.
Myth No. 3: Probiotics Permanently Fix the Gut
Probiotic supplements and foods offer real benefits, but they are not a one-time fix. Once probiotic use stops, the gut tends to revert to its previous bacterial composition. Consistency is what matters. Rajapaksa recommends probiotic-rich foods—yogurt, sauerkraut, miso, kimchi and kefir—as reliable everyday sources, alongside supplements taken daily per package instructions for those who prefer that route.
Myth No. 4: Cut Gluten Before Getting Tested for Celiac Disease
This is one of the more consequential myths, because acting on it can actually undermine a proper diagnosis. Both the blood test and endoscopic biopsy used to detect celiac disease can return falsely normal results if gluten has already been removed from the diet. The only way to get an accurate reading is to continue eating gluten until testing is complete. The diagnostic gold standard—an upper endoscopy with small intestine biopsies—depends on the immune response being actively triggered. Symptoms that might warrant testing include bloating, diarrhea, fatigue, skin rash and abdominal pain. Importantly, celiac disease can emerge in adulthood even in people who consumed gluten for years without any apparent problem.
Myth No. 5: Heartburn Is the Only Sign of Acid Reflux
Many people with acid reflux never experience the classic chest-burning sensation at all. So-called silent reflux can present instead as a persistent cough, chronic throat-clearing, sore throat, burping, bad breath or difficulty swallowing. In some cases, the symptoms are subtle enough that only a dentist or ear-nose-throat specialist notices the telltale effects—often erosion of tooth enamel or throat inflammation. Reflux without heartburn is more common than most people realize, and undiagnosed cases are frequently left untreated for years.
Myth No. 6: Spicy Food Causes Stomach Ulcers
Spicy food can irritate an existing ulcer and intensify the discomfort, but it does not cause ulcers to form. The overwhelming majority of stomach ulcers—roughly the vast majority of cases—are caused by an infection with Helicobacter pylori, a bacterium commonly acquired during childhood that can lie dormant for decades before triggering stomach inflammation or ulceration in adulthood. The second leading cause is regular use of non-steroidal anti-inflammatory drugs such as ibuprofen and aspirin, which erode the stomach lining over time.
The Colon Cancer Screening Myth Nobody Talks About
Perhaps the most dangerous myth of all is the assumption that colon cancer is primarily a family disease. In reality, between 70 and 80 percent of colon cancer cases occur in people with no relevant family history whatsoever—meaning the assumption that screening only matters for people with relatives who had the disease is flatly wrong. Current guidelines recommend that all adults begin screening at age 45. Those with a family history, or who experience symptoms such as rectal bleeding, unexplained weight loss, changes in bowel habits, abdominal pain or anemia, should be screened earlier. As Rajapaksa noted, younger adults are increasingly being diagnosed, making colonoscopy—the gold standard test—more relevant than ever for a broader population.
Source: Today
