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Diagnostics > Gastroscopy

Gastroscopies: All you need to know

Dr. med. André Sommer

Dr. med. André Sommer

In a gastroscopy, a tube with a camera is passed through the mouth into the stomach to detect changes in the mucous membrane of the esophagus, stomach and duodenum. In addition, tissue samples can be taken during the examination, and therapeutic interventions can even be carried out.

When is a gastroscopy performed?

The term gastroscopy is usually used as an abbreviation for esophagogastroduodenoscopy (EGD). This long name indicates that a gastroscopy examines not only the stomach itself but also the esophagus (esophagus) and the part of the intestine adjacent to the stomach (the duodenum). The reasons for when a gastroscopy is performed are also derived from this: Whenever problems are suspected in these three organs, an EGD can be used to examine the mucosa more closely. Typical symptoms that lead to a gastroscopy include:

  • Chronic stomach pain
  • Nausea
  • Vomiting
  • Heartburn
  • Swallowing disorders

Rarely, a gastroscopy is performed to retrieve a swallowed object or to rinse and pump out the stomach in case of poisoning. Another common reason is suspected bleeding that can cause either acute or chronic blood loss. Since approximately 90 percent of gastrointestinal bleeding occurs in the upper digestive tract, a gastroscopy is the most important diagnostic measure for this problem.

Tip: If a gastroscopy is done to rule out an illness with irritable bowel symptoms, the next step is nutritional therapy. Proper nutrition is crucial both in reducing symptoms and increasing quality of life. You can use our digestive health app to investigate the causes of your symptoms and help tackle your problems with an appropriate diet.

What are the symptoms of digestive tract bleeding?

Bleeding can manifest itself, among other things, as “coffee-ground like” or bloody vomit. You may also notice tarry stool or discover blood in the stool via a test (occult blood test). Anemia found in the laboratory can also indicate bleeding in the digestive tract. Bleeding can be treated directly via a gastroscopy.

How is a gastroscopy prepared?

In contrast to a colonoscopy, a gastroscopy does not require long preparation and colon cleansing. The stomach empties quickly and completely on its own, so that it is sufficient to fast on the day of the examination, only drink clear fluids and stop drinking two hours before the procedure. Smoking should also be avoided on the day of the examination, as this also increases the risk of vomiting, which can lead to complications.

If you take anticoagulant medications (“blood thinners”) regularly, you should discuss with the doctor beforehand whether they need to be temporarily suspended, otherwise the risk of bleeding may increase.

How is a gastroscopy performed? How long does a gastroscopy last?

In most cases, a gastroscopy can be performed on an outpatient basis, so it does not require hospitalization. The patient lies in the side position during the examination; usually a plastic splint keeps the mouth slightly open.

  • Local anesthetic: To prevent gagging, the throat is anesthetized by a spray with local anesthesia. The examination usually takes only a few minutes and is not too uncomfortable, which is why anesthesia can be avoided. If desired or for children, it is still possible to initiate short-term anesthesia using a syringe so that the patient does not notice the gastroscopy.
  • Gastroscopy: During the examination, a tube is pushed through the mouth through the esophagus into the stomach and duodenum. In the tube there is a light guide, a camera, and a tool channel through which further instruments can be inserted. The examiner, usually a gastroenterologist, can control and turn the tube via the handpiece so that all angles of the stomach can be recorded on a monitor.
  • Tissue samples: Once the doctor has inspected the entire mucous membrane, small tissue samples are taken from all sections. These biopsies are examined later under a microscope and with certain stains and can thus provide information about changes in the mucous membrane. There is minimal bleeding during tissue removal, but this stops quickly under normal conditions.
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What additional examinations can be done during or after a gastroscopy?

If a conspicuous spot in the gastrointestinal tract is detected during a gastroscopy, this can be examined further. For example, several biopsies are taken from a gastric ulcer to rule out malignant events.

If there is an inflammation of the stomach (gastritis), the bacterium Helicobacter pylori is often responsible for this. In addition to being found in the tissue sample, these pathogens can also be detected by the so-called rapid urease test. A small sample is taken from the stomach, placed in a nutrient medium with urea and the examiner waits until the bacteria convert the urea. If this is the case, an indicator turns red, the bacteria have been detected and can be treated with antibiotics.

With heartburn in particular, it can be of interest whether gastric acid rises into the esophagus. To check this, a probe can be inserted into the esophagus during gastroscopy, which measures the pH value and sends these values wirelessly to a receiver. The pH indicates how acidic something is. The probe remains in the digestive tract for about 48 hours and is then simply excreted.

Which diseases can be recognized by a gastroscopy?

Diseases of the esophagus, stomach and duodenum can be detected through a gastroscopy. For example, mucous membrane protrusions (diverticula), injuries, or inflammation can be detected in the esophagus.

  • Candidiasis: If there is a white layer on the inflammation, it may be thrush or candidiasis, a fungal disease that occurs particularly in people whose immune system is very weak. (Esophageal candidiasis)
  • Reflux disease: Inflammation of the esophagus is also visible in gastroesophageal reflux disease or eosinophilic esophagitis - a biopsy then usually reveals the cause. In the case of reflux disease, it is also important that the tissue does not already show microscopic changes, because these could be the signs of a cancer precursor. Larger structures suspected of tumors are also biopsied.
  • Diaphragmatic hernia: Another possible finding, especially with reflux complaints, can be a hernia in which part of the stomach comes to rest in the chest area (diaphragmatic hernia, hiatal hernia).
  • Varicose veins: If cirrhosis of the liver creates strong pressure in the venous system of the gastrointestinal tract, the veins in the esophagus may expand, which then become visible as varicose veins and pose an increased risk of bleeding.
  • Inflammation: Inflammation can also occur in the stomach, which can be shown, among other things, by a reddish discoloration and increased blood flow. A biopsy can be used to distinguish whether it is a bacterial infection, an autoimmune event, or another cause of this inflammation.
  • Stomach ulcers: It can also be used to detect Helicobacter pylori. A common finding is also a gastric ulcer (ulcer ventriculi), which in most cases is located at the exit of the stomach or in the small bend in the stomach. Bleeding may result from this ulcer. Ultimately, there is also the risk of perforation, in which stomach contents can enter the abdominal cavity. Because there is also a risk of degeneration, tissue samples must be carefully taken here to rule out cancer.
  • Duodenal ulcers: Ulcers (duodenal ulcers) may also be found in the duodenum. They must also be biopsied, although the danger of cancer developing is lower, here.
  • Celiac disease: A biopsy is also necessary if celiac disease is to be detected. With this disease, the villi are destroyed by autoimmune processes and malabsorption occurs, resulting in deficiency symptoms and growth retardation in children.
  • Crohn's Disease: Chronic Inflammatory Bowel Disease often involves the upper parts of the digestive tract. Therefore, a simple colonoscopy is not enough to show the extent of the disease and a gastroscopy is necessary.

Can a gastroscopy also be used therapeutically?

In many disease processes, a gastroscopy can also be used therapeutically. With bleeding, gastric ulcers can be glued or sclerosed, and esophageal varicose veins can also be rendered harmless by sclerotherapy or rubber band ligation. If there is a swallowing disorder due to achalasia, a disease of the mucous membrane nerve network, botox can be injected into the esophageal muscle or the muscle layer can be cut. If the esophagus is severely constricted, for example due to an inoperable tumor, a stent can also be placed. This implant is clamped in the esophagus and keeps it open so that food can pass through it again.

What are the risks associated with a gastroscopy?

Like any medical procedure, a gastroscopy is not without risk. However, it is a low-risk examination that can be carried out on an outpatient basis without any problems. Inserting the tube can damage the teeth or the back of the throat. If the larynx is injured, temporary hoarseness may occur. In the gastrointestinal tract, tissue injuries with bleeding can occur, and in the worst but rarest case, perforation of the organ wall can result.

Tissue extraction can result in slight blood admixtures in the stool after a gastroscopy. These should go away about 24 hours after the exam. Due to the pharyngeal anesthetic, eating and drinking must be avoided for up to an hour after the examination to avoid ingestion. If a general anesthetic has been used, for example with propofol, the ability to drive is restricted for 24 hours and the patient should be picked up by a trusted person.

Should one get a gastroscopy for irritable bowel syndrome?

Since IBS is commonly understood as a diagnosis of exclusion (i.e. all other possible diseases must be excluded beforehand), a gastroscopy before the diagnosis is advisable. Chronic upper abdominal pain can also be due to gastritis or reflux—both can be treated. If a gastroscopy shows no signs of disease, an IBS diagnosis becomes more likely. Most of the time, however, further tests and examinations, such as a colonoscopy, have to be carried out before a final diagnosis can actually be made.

U. Denzer et al. S2k Leitlinie Qualitätsanforderungen in der gastrointestinalen Endoskopie. 2015. Online:, downloaded on 01/07/2016

W. Schmidt-Tänzer, A. Eickhoff, J. F. Riemann. “Ösophago-Gastro-Duodenoskopie.” DMW-Deutsche Medizinische Wochenschrift 136.09 (2011): p. 437-440.

M. Delvaux, G. Gay. “Upper Gastrointestinal Endoscopy.” In: M. Classen, G. N. J. Tytgat, C. J. Lightdale: Gastroenterological Endoscopy. Zweite Ausgabe. Stuttgart: Thieme; 2010: p. 106-117.

G. M. Eisen, T. H. Baron, J. A. Dominitz et al. “Complications of upper GI endoscopy.” Gastrointestinal Endoscopy. 2002; 55. p. 784-793.

Dr. med. André Sommer

Dr. med. André Sommer

I’m André, a medical doctor from Berlin. Together with a team of medical doctors, nutritionists and data scientists we empower people to understand digestive issues with our app Cara Care.

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