A gastroscopy can be used to check symptoms or confirm a diagnosis (diagnostic gastroscopy), or it can be used to treat a condition (therapeutic gastroscopy).

Checking symptoms

A diagnostic gastroscopy may be recommended if you have symptoms that suggest a problem with your stomach, which may also affect your oesophagus (gullet) or the first section of your small intestine (duodenum).

Symptoms that are often investigated include:

• difficulties swallowing or pain when swallowing (dysphagia)
• persistent abdominal pain
• persistent nausea and vomiting
• unexplained weight loss

A diagnostic gastroscopy can also be used if bleeding inside your stomach or small intestine is suspected. Persistent bleeding can significantly reduce the number of red blood cells in your body (anaemia).

Symptoms of anaemia include:

• feeling tired all the time
• breathlessness
• pale skin
• irregular heartbeats

In some cases, bleeding inside the gastrointestinal (GI) tract can be sudden and massive, and cause symptoms such as:

• vomiting blood
• passing stools (faeces) that are very dark or ‘tar-like’
• a sudden, sharp pain in your abdomen that gets steadily worse

These symptoms usually require immediate investigation with a diagnostic gastroscopy.

Confirming a diagnosis

A diagnostic gastroscopy is also used to help confirm (or rule out) suspected conditions, such as those listed below.

• Stomach ulcer (also known as peptic ulcer disease) - open sores that develop on the lining of the stomach and small intestine.
• Gastro-oesophageal reflux disease (GORD) - a condition where stomach acid leaks back up into the oesophagus.
• Barrett's oesophagus - where abnormal cells develop on the lining of the oesophagus.
• Portal hypertension - where the blood pressure inside the liver is abnormally high, causing swollen veins (varices) to develop on the lining of the stomach and oesophagus.
• Stomach cancer and oesophageal cancer -the endoscope can be used to remove samples of suspected cancerous tissue for testing. This is known as a biopsy.

Therapeutic gastroscopy

The two most common uses of a therapeutic gastroscopy are:

• to stop bleeding inside the stomach or oesophagus - bleeding is commonly caused by a stomach ulcer, gastro-oesophageal reflux disease, or enlarged veins (varices) on the lining of the oesophagus or stomach.
• to widen a narrowed oesophagus that's causing pain or swallowing difficulties (dysphagia).

The oesophagus can become narrowed or blocked for a number of reasons, including mouth cancer or lung cancer, radiotherapy, or an infection, such as tuberculosis or herpes simplex.

A gastroscopy that's used to widen the oesophagus is also known as a ‘gastroscopy with oesophageal dilatation’.

Other uses of therapeutic gastroscopy include:

• treating cases of early-stage stomach cancer or throat cancer by removing any tumours (advanced cases will require more extensive surgery)
• removing non-cancerous growths (polyps) that are causing an obstruction
• removing objects that have become lodged in the oesophagus or stomach
• providing nutrients by way of a feeding tube, when a person is unable to eat in the normal way