A diagnostic upper gastrointestinal (GI) endoscopy, also known as an upper GI scopy, is a medical procedure used to examine the interior lining of the upper part of the digestive tract. This includes the esophagus, stomach, and the first part of the small intestine (duodenum). During the procedure, a flexible tube with a light and camera at the end, called an endoscope, is inserted through the mouth and gently guided down the throat. This allows the physician to directly visualize the mucosal surfaces, identify abnormalities, and take photographs if necessary. Additionally, a biopsy may be performed, wherein small tissue samples are taken from suspicious areas for further pathological examination. This is crucial for diagnosing conditions such as gastritis, ulcers, celiac disease, and cancers. The procedure is typically performed under mild sedation to ensure patient comfort, and it generally has a low risk of complications. The results from the endoscopy and biopsy provide valuable information that aids in the accurate diagnosis and appropriate management of various upper GI disorders.