Functional dyspepsia: symptoms, causes, treatment and diet

Dyspepsia is the medical word for indigestion: a group of symptoms such as upper belly pain, belching, bloating and feeling full. NHS inform describes indigestion as pain or discomfort in the upper abdomen (dyspepsia) or a burning pain behind the breastbone (heartburn), which may occur together or on their own.

Functional dyspepsia is the diagnosis when no disease is found to explain those symptoms. Guts UK explains that this does not mean the symptoms are not real. It points instead to a communication issue between the brain and the gut, in which the nerves of the stomach are oversensitive.

Guts UK says functional dyspepsia is the most common cause of dyspepsia symptoms and is ultimately diagnosed in 8 out of 10 cases of indigestion. It reports that around the world 7 in every 100 people have it, that more women than men have it in the UK, and that slightly more adults are diagnosed between the ages of 18 and 39 than in older age groups.

Guts UK lists the following symptoms. They can range from mild to severe and change over time, sometimes happening less often and sometimes more.

• Upper belly (abdominal) pain, from mild to severe, that may feel like burning.

• Feeling sick (nausea).

• Belching (burping).

• Bloating.

• An uncomfortable feeling of being full after eating regular-sized meals.

Guts UK says some people get pain soon after eating, which doctors call postprandial distress syndrome, while others have symptoms unrelated to food, which may be called epigastric pain syndrome. In 1 in 3 people with functional dyspepsia the two patterns overlap.

Some people also have heartburn (pain under the breastbone). Guts UK advises contacting your GP if heartburn symptoms worsen with exercise or activity.

It also notes that irritable bowel syndrome (IBS) affects roughly 1 in 3 people who have functional dyspepsia, with symptoms such as belly pain, bloating and a change in how often or how loose the poo is. Coeliac disease testing is recommended in people with functional dyspepsia and IBS symptoms.

Guts UK says there is currently no cure for functional dyspepsia, but most treatments help to reduce symptoms to a manageable level, and only a small number of people still have severe symptoms after treatment. If first-line treatments from a GP do not work, you can ask to be referred for specialist care, for example to a gastroenterologist or a psychologist.

The NHS says there is usually no need to see a GP for ordinary indigestion because a pharmacist can recommend antacids, alginates or proton pump inhibitors, and some medicines are best taken after eating because their effects last longer.

Guts UK says food can worsen symptoms, especially if they occur with eating, but sensitivity varies and many people with functional dyspepsia tolerate some or all foods. It suggests that for some people cutting back on caffeine-containing food and drinks, spicy foods, fatty foods such as chocolate and pastries, citrus juices, peppermint, fizzy drinks and tomatoes can be helpful, and that eating smaller, more frequent meals can also reduce symptoms.

The charity warns that avoiding many foods can lead to malnourishment and that foods should be reintroduced if cutting them out has not improved symptoms. It says there is no evidence at present to support elimination diets and no proof that a specific probiotic or prebiotic supplement is effective.

The NHS adds some general indigestion advice: cut down on tea, coffee, cola or alcohol, raise your head and shoulders in bed, do not eat 3 to 4 hours before bed, avoid rich, spicy or fatty foods and do not take ibuprofen or aspirin unless prescribed.

Guts UK says there is no single known cause. The gut and brain communicate constantly through nerves, and in functional dyspepsia they may overshare information so that the connection becomes more sensitive. It describes the gut nerves becoming more sensitive to normal function, with the stomach not emptying properly.

Other contributors it lists include changes in the gut bacteria after an infection, stress, lifestyle factors and the emotional response to symptoms. Smoking, alcohol above recommended levels and high levels of anxiety or stress can all make symptoms worse.

Medicines can play a part too. Guts UK says opioid-based painkillers such as codeine, tramadol and morphine can intensify discomfort, heartburn and reflux and may slow stomach emptying, and NHS inform notes that anti-inflammatory painkillers such as ibuprofen and aspirin can cause indigestion. Do not stop a prescribed medicine without speaking to your doctor or pharmacist first.

Guts UK says that when any additional tests do not reveal a disease causing the symptoms, functional dyspepsia is diagnosed from the pattern of symptoms. Testing for Helicobacter pylori (H. pylori), a stomach bacterium that can occasionally cause symptoms, should be done using a simple blood, stool or breath test. If it is found, treatment should be given, and a further test checks that it has gone, although some people continue to have symptoms afterwards.

Your doctor may arrange more tests if you are over 40 or have a family history of an oesophageal, stomach or pancreatic cancer, according to Guts UK. Tests might include blood tests, a camera test of the gullet and stomach (gastroscopy) or scans. In functional dyspepsia, the lining of the gut looks normal on gastroscopy and other test results are normal.

NHS inform says that your pharmacist may advise seeing your GP if you have recurring indigestion and are 55 or over, or have the warning symptoms listed below. You may then be referred for an endoscopy to rule out a serious cause.

Most indigestion is not serious, but the NHS lists symptoms that need a GP appointment. Guts UK lists a similar set of red-flag symptoms to report to your doctor. Most people with them will not have cancer, but earlier diagnosis helps treat any serious condition sooner.

• Losing a lot of weight without meaning to.

• Difficulty swallowing, or pain or a sensation of food sticking when swallowing.

• Persistently being sick, or vomiting blood, or blood in your poo.

• Iron deficiency anaemia (the NHS lists this; Guts UK lists low iron in the blood, with tiredness and breathlessness).

• A lump in your stomach.

• Belly pain that travels through to the back.

• Yellowing of the whites of the eyes, dark urine and pale poo.

• Indigestion that keeps coming back or severe pain.

Guts UK says most people's symptoms become better over time and with treatment, though a small number continue to have dyspepsia long term. Routine visits to the doctor are not typically necessary, but you should go back if your symptoms change or red-flag symptoms develop.

The charity notes that living with symptoms for which no disease has been found can reduce quality of life and bring a sense of hopelessness, and that stress can make symptoms worse. It encourages people to tell their doctor if they feel this way so that the right care can be offered.

Questions Guts UK suggests asking your doctor include whether you could be referred to a dietitian, whether a specialist could consider additional therapies if medicines and simple fixes have not helped, and whether to take medicines regularly or only when needed.

Most people start with a pharmacist or GP. A GP can arrange H. pylori testing and first-line medicines, and can refer you to a gastroenterologist, an NHS dietitian or psychological services if symptoms persist.

Some people choose a private gastroenterology consultation or private gastroscopy, usually with a referral letter. Tests that look inside the stomach are done to rule out other conditions rather than to treat functional dyspepsia itself.