Esophagogastroduodenoscopy (EGD) or oesophagogastroduodenoscopy (OGD), also called by various other names, is a diagnostic endoscopic procedure that visualizes the upper part of the gastrointestinal tract down to the duodenum.

The term gastroscopy literally focuses on the stomach alone, but in practice, the usage overlaps.

Nonetheless, findings such as excess fluid or poor motion of the gut during endoscopy can be suggestive of disorders of function.

The endoscope is quickly passed through the stomach and through the pylorus to examine the first and second parts of the duodenum.

Once this has been completed, the endoscope is withdrawn into the stomach and a more thorough examination is performed including a J-maneuver.

This involves retroflexing the tip of the scope so it resembles a 'J' shape in order to examine the fundus and gastroesophageal junction.

Clinical practice varies with respect to routine biopsy for histological analysis of the examined upper gastrointestinal system.

A rapid urease test is quick, easy, and cost-effective screening for Helicobacter pylori infection.