Gastroscopy (Upper GI Endoscopy)

Understand

Overview

Gastroscopy, also called esophagogastroduodenoscopy (EGD) or upper gastrointestinal endoscopy, involves inserting a flexible, camera-tipped endoscope through the mouth to directly visualize the mucosal lining of the esophagus, stomach, and the initial portion of the duodenum. Like colonoscopy for the lower GI tract, gastroscopy is both a diagnostic and therapeutic procedure — through the endoscope's working channel, doctors can take tissue samples for histopathology, test for Helicobacter pylori, control bleeding, or dilate an esophageal stricture.

The clinical value of gastroscopy comes from being the only test that directly visualizes and simultaneously biopsies the upper GI mucosa — no imaging test (abdominal ultrasound, CT scan) offers comparable resolution for assessing subtle mucosal changes such as early ulcers, erosions, intestinal metaplasia of the esophageal lining (Barrett's esophagus), or suspicious neoplastic lesions. Unlike functional tests such as esophageal pH monitoring, gastroscopy assesses tissue structure rather than function, making the two types of tests complementary rather than interchangeable.

The test is ordered in a wide range of clinical contexts. The most common indication involves so-called alarm symptoms accompanying upper GI complaints — difficulty swallowing (dysphagia), unintentional weight loss, persistent vomiting, gastrointestinal bleeding (coffee-ground vomiting, black tarry stools), or iron-deficiency anemia without an obvious cause. Another common indication is chronic, treatment-resistant gastroesophageal reflux disease, especially in people over 45–50 or with additional risk factors, where the goal is to rule out Barrett's esophagus or early neoplastic changes. Gastroscopy is also routinely ordered when Helicobacter pylori infection is resistant to treatment, for monitoring known precancerous stomach lesions, and for urgent workup of acute upper GI bleeding.

On the practical side, preparation for gastroscopy is much simpler than for colonoscopy — it only requires fasting, usually for 6–8 hours before the procedure, without any laxative preparation. The procedure itself usually takes 5–15 minutes and can be done with local throat anesthesia (a spray) with or without additional intravenous sedation, depending on patient and facility preference. Afterward, it's recommended to avoid eating and drinking for an hour or two due to the throat numbing, to prevent aspiration. The doctor usually shares macroscopic findings right away, while histopathology results for any biopsies are typically available after 1–2 weeks.

Several recurring misconceptions surround gastroscopy. Some patients worry the procedure will involve gagging or vomiting throughout its entirety — in reality, modern, thin endoscopes and local throat anesthesia significantly reduce the gag reflex, and for most patients the experience comes down to a few uncomfortable but brief moments at the start of the exam. Another misconception is treating reflux symptoms as sufficient grounds for self-diagnosis without a test — many more serious conditions, including early neoplastic changes, can produce symptoms identical to ordinary heartburn.

Gastroscopy remains the first-line test for alarm symptoms and chronic upper GI complaints, combining the precision of direct visual mucosal assessment with the ability to immediately take diagnostic material or perform a therapeutic intervention. The decision about indications for the test, its urgency, and the frequency of any follow-up exams is worth discussing individually with your doctor, taking into account the nature of your symptoms, age, and individual risk factors.