The pandemic has changed the way we think about illness and recovery. While many people bounce back from COVID within a couple of weeks, others are left dealing with ongoing symptoms. These lingering effects, now widely referred to as Long COVID, are known to affect everything from energy levels to memory and even the gut.
New research has found a link between Long COVID and a cluster of conditions known as disorders of gut-brain interaction (DGBIs). These include irritable bowel syndrome (IBS), functional dyspepsia, and other bowel disturbances that have an impact on quality of life.
This discovery adds to what we already know about the gut-brain axis (a complex, two-way communication system). When disrupted, it can lead to changes in motility, sensitivity, and even how we perceive pain or discomfort in the gut.
What the study found
The recent study looked at data from 2017 to 2023 of people who had previously tested positive for COVID. What stood out was that those with Long COVID symptoms were significantly more likely to report new or worsening gastrointestinal issues that met the criteria for a DGBI. Reports of IBS were up by 28% and dyspepsia by almost 44%.
People who had no previous history of IBS or functional bowel issues were now experiencing persistent bloating, abdominal pain, irregular bowel habits, and food intolerances, well beyond the usual post-viral recovery period.
These symptoms weren’t random. They reflected patterns typically seen in disorders that are influenced by a mix of nervous system changes, immune system activity, and gut microbiome shifts. This suggests that COVID may be leaving a more lasting imprint on the digestive system than first thought.
How COVID might be affecting the gut-brain axis
There’s still a lot to learn, but there are several theories. One involves low-grade inflammation in the gut lining. When the body responds to an infection like COVID, it activates the immune system. In some people, that immune response doesn’t switch off as it should. Persistent inflammation, particularly in the gastrointestinal tract, can affect how the nerves in the gut behave, making them more reactive to normal stimuli like stretching or certain foods.
Another possibility is a change in the gut microbiome. We know that COVID can alter the diversity of bacteria living in the gut, reducing the numbers of helpful species and allowing less beneficial ones to take over. This imbalance can affect digestion, nutrient absorption, and even mood, since many of the brain’s chemical messengers, like serotonin, are influenced by what happens in the gut.
Finally, there’s the role of the vagus nerve, which acts as a communication superhighway between the gut and the brain. Post-viral inflammation or stress-related changes to this nerve may amplify sensations from the bowel, leading to increased pain sensitivity or discomfort even when there’s no visible cause.
What this means for patients
If you’ve noticed new digestive symptoms in the months after a COVID infection, such as bloating, cramping, or unpredictable bowel habits, this may be a sign that the gut-brain axis has been affected. These symptoms may improve gradually, but they may persist and require active management.
At the Warwick Bowel and Hernia Clinic, we offer a comprehensive assessment to diagnose your condition and the root cause, with a range of tests and scans at our disposal. We can provide individualised management strategies involving a combination of diet changes, gut-directed therapies, stress reduction, and sometimes medication to calm the nervous system’s response.
If you are experiencing digestive issues or any worrying symptoms, book an appointment with the Warwick Bowel and Hernia Clinic today.
