Chronic constipation is one of the most common — and most frustrating — health complaints in the United States. Millions of adults have followed every recommendation: more fiber, more water, more exercise, different laxatives. And yet, week after week, the problem persists. A leading gastroenterologist based in New York City says the reason may have nothing to do with any of those factors.
Dr. Gina Sam, MD, a board-certified gastroenterologist and former director of the Gastrointestinal Motility Center at Mount Sinai Medical Center, has spent over two decades studying why digestion slows — and why conventional treatments so often fail. Her explanation centers on a group of microorganisms that most doctors rarely discuss: methane-producing archaea.
What Are Archaea, and Why Do They Matter?
Most people have heard about gut bacteria. But archaea are different — ancient, single-celled microorganisms that have lived in the human digestive tract for hundreds of thousands of years. Unlike bacteria, archaea are not targeted by standard probiotics or common gut health interventions. And according to Dr. Gina Sam, MD, that's precisely why so many people with chronic constipation never find lasting relief.
A 2020 study in the American Journal of Gastroenterology confirmed what some gastroenterologists had suspected: methane gas produced by archaea overgrowth in the large intestine directly slows intestinal transit time — the rate at which the colon moves waste through the body.
Standard interventions simply don't address what's happening deeper in the large intestine. Most of my patients have tried everything before walking into my office.— Dr. Gina Sam, MD · Board-Certified Gastroenterologist · Former Director, Mt. Sinai GI Motility Center
When archaea populations become overgrown, they produce methane as a metabolic byproduct. That methane interferes with peristalsis — the rhythmic muscle contractions that push waste through the colon. The result: a colon that moves too slowly, waste that dries out and hardens, and a cycle that gets worse the longer it continues.
Why Standard Probiotics Don't Reach the Problem
A 2019 study in the Microbiome Journal found that the vast majority of commercially available probiotic bacteria are destroyed by stomach acid before reaching the large intestine — which is precisely where archaea overgrowth occurs. In other words, the part of the gut where chronic constipation originates is largely untouched by the products most people use to try to fix it.
Research note: Methane gas doesn't only cause bloating. Studies show it actively slows the electrical signaling in the enteric nervous system — the nerve network lining the gut — reducing the frequency and strength of peristaltic contractions. This produces a distinctly resistant type of constipation that doesn't respond to fiber or fluids.
Continue watching — Dr. Gina Sam's full video explanation, free
Watch Dr. Gina Sam's Full Explanation →The Downstream Effects Most People Don't Connect
Dr. Gina Sam, MD also addresses why chronic gut dysbiosis of this kind extends well beyond constipation. When waste moves too slowly, fermentation increases, producing gases that cause persistent bloating and cramping. And because approximately 90–95% of the body's serotonin is manufactured in the gut, chronic disruption to the large intestine's microbial environment has been linked to low mood, brain fog, and persistent fatigue — symptoms that many sufferers never connect to their digestive system.
In her video, Dr. Gina Sam walks through the science behind all of this in detail — why fiber and probiotics miss the target, what the peer-reviewed research shows about the large intestine, and what she has found clinically effective for patients who have struggled for years.