Functional dyspepsia is chronic indigestion that has no identifiable structural cause. The word “functional” means that the symptoms cannot be explained by the usual physical causes found on examination or testing. It is also known as non-ulcer dyspepsia.
Functional dyspepsia is classified as a disorder of gut-brain interaction, reflecting the close two-way connection between the digestive system and the nervous system, and how the body senses and processes sensations from the gut. Under the Rome IV framework, there are two main subtypes:
- Postprandial distress syndrome (PDS) — symptoms related to meals, such as uncomfortable fullness and early satiety after eating
- Epigastric pain syndrome (EPS) — pain or burning in the upper abdomen, not necessarily related to meals
Some people have a mix of both subtypes.
The main symptoms of functional dyspepsia are:
- Pain or burning in the upper abdomen (epigastric pain or burning)
- An uncomfortable feeling of fullness after eating (postprandial fullness)
- Feeling full very quickly, before finishing a normal-sized meal (early satiety)
- Bloating in the upper abdomen
- Nausea
- Excessive belching
Causes and Risk Factors
There is no single cause, and several mechanisms are thought to contribute:
- Over-sensitivity of the nervous system to normal digestive sensations (visceral hypersensitivity)
- Problems with how the stomach moves and relaxes, including the stomach not relaxing properly to accommodate food, or emptying more slowly than normal
- Changes in gut bacteria, including Helicobacter pylori infection, which can inflame the stomach lining
- Low-grade inflammation in the duodenum, sometimes triggered by a previous infection or a food reaction
- Disturbance in the communication between the gut and the brain
Recognised risk factors include being female, use of anti-inflammatory painkillers, smoking, anxiety or depression, a history of childhood physical or sexual abuse, and Helicobacter pylori infection.
Diagnosis
Functional dyspepsia is mainly a clinical diagnosis, made once other causes have been ruled out, such as gastroesophageal reflux disease, peptic ulcer disease and gastroparesis. Tests used may include blood tests, Helicobacter pylori testing (by breath test, stool test or biopsy), upper endoscopy, and, in selected cases, a gastric emptying study.
Guidelines advise a stepwise approach based on age and warning signs:
- People under 60 are usually first tested for Helicobacter pylori and treated if positive; if symptoms persist, acid-suppressing medication is tried
- People aged 60 and over are generally offered an upper endoscopy to exclude other conditions, including cancer
Younger people who have warning signs or a higher risk of cancer may also be offered an endoscopy earlier.
Treatment and Management
Treatment is directed at symptoms and often combines several approaches:
- Helicobacter pylori eradication — a course of antibiotics with acid suppression when the infection is present
- Acid-suppressing medication — proton pump inhibitors and H2 blockers
- Prokinetics — medicines that help the stomach empty, particularly useful for the postprandial distress subtype
- Neuromodulators — low-dose tricyclic antidepressants, which reduce the perception of pain from the gut
- Psychological and behavioural therapies — counselling, relaxation techniques and stress reduction
- Dietary and lifestyle changes — smaller, more frequent meals, eating slowly, and avoiding trigger foods such as fatty, spicy or carbonated items, caffeine and alcohol
Treatment is often adjusted over time to find the combination that works best for each person.
Prognosis
Functional dyspepsia is a chronic, relapsing condition, meaning symptoms tend to come and go over time. While it can significantly affect quality of life, it is not harmful and does not cause serious damage. Many people find relief with treatment, although symptoms may not disappear completely.
When to See a Doctor
Seek medical attention promptly for any of the following warning signs:
- Vomiting blood
- Dark, tarry stools
- Difficulty swallowing
- Unexplained weight loss
- Persistent vomiting
- Fatigue or signs of anemia
Shortness of breath, or pain in the jaw, neck or arm alongside abdominal symptoms, should be treated as an emergency, as it may indicate a heart problem. You should also see a doctor if your symptoms change, worsen, or have not been evaluated before.