An EGD (esophagogastroduodenoscopy), also called an upper endoscopy, is used to diagnose conditions affecting the esophagus, stomach, and the first part of the small intestine. It can identify ulcers, acid reflux damage, celiac disease, infections, inflammatory conditions, and early-stage cancers. A thin, flexible tube with a camera is guided down your throat, giving your doctor a direct view of your upper digestive tract and the ability to take tissue samples on the spot.
Acid Reflux and Esophageal Damage
One of the most common reasons for an EGD is to evaluate damage caused by chronic acid reflux (GERD). The camera can reveal inflammation, erosions, or narrowing in the esophagus caused by years of stomach acid washing upward. If the damage is significant, the lining of the lower esophagus can change in a way that increases cancer risk, a condition called Barrett’s esophagus. EGD is considered the gold standard for screening for Barrett’s, and when it’s found, biopsies are taken to check whether the cells are becoming abnormal. Catching these changes early allows for treatment before they progress to esophageal cancer.
Peptic Ulcers and H. Pylori Infection
An EGD gives a clear, direct look at ulcers in the stomach or duodenum (the first section of the small intestine). Your doctor can see the size, depth, and location of an ulcer and take biopsies to rule out anything more serious.
During the same procedure, tissue samples can be tested for H. pylori, a bacterium that causes most peptic ulcers. The most common method is a rapid urease test: a small tissue sample is placed on a test strip that changes color if H. pylori is present. Results from this test can come back in minutes, sometimes while you’re still in the recovery area. If the initial result is unclear, the biopsy samples can also be examined under a microscope in a pathology lab for confirmation.
Celiac Disease
Blood tests can suggest celiac disease, but an EGD with biopsies is needed to confirm it. The diagnosis depends on a combination of your symptoms, blood work, and what the tissue samples show under a microscope. Current guidelines recommend taking at least six biopsies: one or two from the duodenal bulb and at least four from further down in the duodenum. Multiple samples are necessary because celiac damage can be patchy, and a single biopsy could miss affected areas entirely.
During the procedure, your doctor may notice visual clues like flattened or scalloped folds in the small intestine, though these signs aren’t always obvious. Standard upper endoscopy detects visible signs of intestinal damage only about 55% of the time, which is why the microscopic analysis of biopsies is the more reliable piece of the puzzle.
Eosinophilic Esophagitis
If you have trouble swallowing, feel like food gets stuck in your chest, or experience unexplained chest pain, your doctor may suspect eosinophilic esophagitis (EoE), a chronic allergic condition where a specific type of immune cell builds up in the esophagus lining. An EGD is the only way to diagnose it. The endoscope may show rings, furrows, or white patches in the esophagus, but the definitive diagnosis comes from biopsies. A pathologist counts the immune cells in the tissue, and a count of 15 or more per high-power field confirms EoE.
Esophageal and Stomach Cancers
An EGD is a primary tool for detecting cancers of the esophagus and stomach. The camera allows your doctor to spot suspicious growths, discolored patches, or irregular tissue and immediately biopsy anything that looks abnormal. For people already known to have Barrett’s esophagus, regular surveillance EGDs are used to catch precancerous changes early enough for treatment before full cancer develops. This is one of the procedure’s most important roles: identifying disease at a stage when it can still be treated with minimally invasive techniques rather than major surgery.
What the Procedure Involves
An EGD typically takes 15 to 30 minutes. You’ll need to stop eating solid food at least eight hours beforehand and stop drinking clear liquids about four hours before. Most people receive conscious sedation, which means you’ll feel relaxed and drowsy but won’t be fully asleep. A numbing spray is also applied to your throat to reduce discomfort as the endoscope passes through. You breathe normally throughout the procedure since the tube doesn’t block your airway.
If biopsies are taken, you won’t feel them. The lining of the digestive tract doesn’t have the same pain-sensing nerves as your skin. Afterward, you may have a mild sore throat for a day or two.
When Biopsy Results Come Back
Your doctor can often share what they saw through the camera the same day, sometimes before you’ve fully shaken off the sedation. Biopsy results take longer because tissue samples need to be processed and examined by a pathologist. For most conditions, results arrive within a few weeks but can take up to two months. If cancer is suspected, results are typically prioritized and returned within two weeks.
Risks of the Procedure
A diagnostic EGD, where the doctor is looking and possibly taking small biopsies, is very safe. Serious complications are rare. The risk profile changes when the procedure includes therapeutic interventions like stretching a narrowed section of the esophagus or treating bleeding veins. Dilating a simple stricture carries a perforation risk of around 2%, while more complex or cancerous strictures carry higher risks. For a straightforward diagnostic exam without these additions, the chance of a significant complication is much lower. Most people go home the same day and return to normal activities by the following morning.