Irritable stomach syndrome (functional dyspepsia)

Everyone has probably experienced a feeling of fullness, stomachache, and nausea at some point in their lives. However, anyone experiencing these symptoms repeatedly over a period of months should visit their doctor. Indigestion (an irritable stomach) might be the cause.

At a glance

  • Approximately 5 to 11% of people have indigestion.
  • The typical symptoms are a feeling of fullness, early satiety, stomachache, and heartburn.
  • There are many possible causes and these have not been definitively clarified.
  • The disease is diagnosed on the basis of symptoms and by ruling out other diseases.
  • There are various treatment options. 

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Functional dyspepsia (indigestion): man in suit and tie sitting at the kitchen table. An empty plate and coffee cup in front of him. He is holding his stomach as he looks as if he is about to belch painfully. His face is tense.

What is indigestion?

Irritable stomach syndrome (indigestion) is one of the most common diseases of the gastrointestinal tract. Doctors also use the term “functional dyspepsia”.

Symptoms affect the upper abdomen and can vary greatly. A feeling of fullness, early satiety, stomachache, and heartburn are typical. The causes of irritable stomach syndrome are not fully understood. Many factors are probably involved. Although there is no causal therapy, there are various treatment options, ranging from medication to psychotherapeutic treatment.

What are the symptoms of indigestion?

Symptoms can vary greatly and can also be nonspecific. The most common symptoms include:

  • feeling of fullness after eating
  • early satiety
  • stomachache or acid indigestion 
The most frequent symptoms of functional dyspepsia (indigestion) are feeling of fullness after meals, achieving satiety quickly, stomach ache or heartburn.

Some people with indigestion also report nausea, vomiting, or heartburn.

What causes indigestion?

The causes of indigestion are not fully understood. Possible factors include:

  • impaired gastric emptying
  • increased sensitivity to pain in the stomach
  • an infection with the bacterium Helicobacter pylori
  • imbalance of intestinal bacteria in the upper gastrointestinal tract
  • inflammation of the duodenum
  • mental causes, e.g. persistent stress as well as anxiety and depression

How common is indigestion?

Irritable stomach syndrome is a common disease: approximately every tenth person has indigestion. Women are more susceptible than men.

Around one in ten people suffer from functional dyspepsia (indigestion).

How does indigestion develop?

Indigestion is chronic in approximately 4 out of 5 people, i.e. they experience symptom-free periods followed by periods of recurrence. The severity of symptoms can vary during each recurrence.

How is indigestion diagnosed?

Irritable stomach syndrome is diagnosed when at least one of the typical symptoms (feeling of fullness after eating, early satiety, stomachache, or heartburn) is present for 3 months during a 6-month period.

It is also important to rule out other causes of the symptoms, e.g. a stomach ulcer or duodenal ulcer, stomach cancer, gastritis, and gastroesophageal reflux disease. Taking certain medications, e.g. pain medication, can also cause stomach problems.

Doctors will ask patients about their medical history and symptoms. A physical examination and blood test and sometimes an endoscopic examination of the esophagus, stomach, and duodenum (“gastroscopy”) are then performed.

If “irritable stomach syndrome” is diagnosed, a special breath test is performed to determine whether Helicobacter pylori bacteria are present in the stomach if the test was not already performed during gastroscopy.

How is indigestion treated?

If Helicobacter pylori bacteria is detected, a combination of antibiotics and proton pump inhibitors (PPIs) like omeprazole or pantoprazole is used for treatment. If there is no Helicobacter pylori infection, the doctor will prescribe only a proton pump inhibitor to treat the indigestion. These medications inhibit acid production thus reducing the amount of stomach acid.

A further treatment option is H2 receptor antagonists, also known as H2 blockers. These medications reduce the acid content in the stomach. If this treatment is not effective, antidepressants or prokinetic agents can be a further option. The latter are medications that promote gastrointestinal motility. If none of the medications are effective, psychotherapy is another possibility.

Finally, dietary changes or avoiding certain foods might provide relief. Studies have shown that wheat, caffeine, and fatty foods can trigger symptoms of indigestion.

How does indigestion affect everyday life?

Some simple steps can be taken to help manage indigestion. For example, self-monitoring and keeping a diary of symptoms can be used to determine if certain foods trigger symptoms.

Sometimes, avoiding foods or drinks that are not well tolerated can provide relief. It can also be helpful to:

  • eat regularly.
  • avoid large meals.
  • chew properly.
  • eat slowly.

Relaxation exercises also help some people to alleviate symptoms. It can also be helpful to remember that indigestion is not a dangerous disease.

Particularly if the symptoms are recurrent, it is important to accept the disease and learn to manage it.

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen – IQWiG). As at:

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