Introduction
Functional Dyspepsia is a disorder similar to Irritable Bowel Syndrome (IBS), which affects the stomach rather than the bowel, and just like IBS, it is diagnosed after ruling out underlying structural or biochemical causes such as peptic ulcers, gastritis, or Gastro-Esophageal Reflux Disorder (GERD).
Symptoms of Functional Dyspepsia may include pain or burning called epigastric pain syndrome (EPS), getting full quickly when eating, and/or feeling excessively full after eating called postprandial distress syndrome (PDS), feeling bloated, or experiencing reflux. Significantly, not all individuals have the same symptoms.
Functional Dyspepsia and IBS Surge After the Pandemic
A recent study [1] of over 4000 adults in both the US and UK that was done in two stages (a) in 2017 before the pandemic then (b) again in 2023, after the pandemic found that Functional Dyspepsia rose almost 44% (from 8% to 12%), and IBS increased 28% (from 5% to 6%) after the pandemic. It was also found that Functional Dyspepsia and IBS were often associated with people experiencing long-COVID, or diagnosed with anxiety disorder, or depression.
The Role of the Gut-Brain Axis
Functional Dyspepsia is sometimes referred to as having a “nervous stomach” because of the known interaction between the gut and the brain, along what is called the gut-brain axis. The gut-brain axis involves the vagus nerve, which is the longest nerve in the human body and which connects the brain to the organs, including the stomach, intestines, heart, and lungs.
Since symptoms of Functional Dyspepsia and some cases of IBS are more pronounced when the individuals are under stress, interventions may not only include dietary modifications, but may also include behavior interventions that can help relax the gut by affecting the vagus nerve.
Symptoms Vary Between Individuals
Individuals with Functional Dyspepsia may experience some symptoms, but not others, so dietary treatment must be individualized for each person, and some of the interventions used may be similar to those used for other functional disorders, such as IBS, or for digestive disorders such as Gastro-Esophageal Reflux Disorder (GERD), hiatus hernia, or Small Intestinal Bacterial Overgrowth (SIBO), or interventions that are unique to Functional Dyspepsia.
For example, addressing the symptom of bloating may involve the use of a low-FODMAP diet implemented over three stages, which is also used in some individuals with Irritable Bowel Syndrome (IBS), depending on which foods are causing the symptoms.
If acid reflux is one of the symptoms that people are experiencing, dietary interventions and lifestyle interventions may be similar to those used in Gastro-Esophageal Reflux Disorder (GERD), or to help decrease stomach pain, dietary recommendations may involve reducing irritants such as spices, alcohol, coffee, and caffeine.
Role of Behaviour Interventions in Functional Dyspepsia
Since Functional Dyspepsia (and sometimes IBS, as well) involves gut-brain interaction, there are some behavioral interventions that are often used, such as specific types of breathing exercises that affect the vagus nerve, help relax the gut, thus minimizing symptoms.
Some Final Thoughts
Functional disorders like Functional Dyspepsia or IBS are diagnosed based on symptoms, rather than lab tests, because they don’t involve a structural or biological abnormality. As with IBS, a diagnosis of Functional Dyspepsia is made by a doctor after ruling out disease states or biological causes. Just as the diagnosis of Functional Dyspepsia is made based on symptoms, so too is the determination of which dietary modifications will be most appropriate.
More Info?
Learn about me and how I can help support you with dietary changes related to Functional Dyspepsia or IBS. View my Irritable Bowel Syndrome (IBS) Package, which also has a Functional Dyspepsia add-on.
To your good health!
Joy
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Reference
- Palsson, Olafur et al. The Prevalence and Burden of Disorders of Gut-Brain Interaction (DGBI) before versus after the COVID-19 Pandemic, Clinical Gastroenterology and Hepatology, Volume 0, Issue 0. [https://doi.org/10.1016/j.cgh.2025.07.012]

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Joy is a Registered Dietitian Nutritionist and owner of BetterByDesign Nutrition Ltd. She has a postgraduate degree in Human Nutrition, is a published mental health nutrition researcher, and has been supporting clients’ needs since 2008. Joy is licensed in BC, Alberta, and Ontario, and her areas of expertise range from routine health, chronic disease management, and digestive health to therapeutic diets. Joy is passionate about helping people feel better and believes that Nutrition is BetterByDesign©.