Gastrointestinal endoscopy is a medical procedure that involves using a thin, flexible tube with a camera and light source at the end to examine the inside of the gastrointestinal tract, including the esophagus, stomach, and intestines. This procedure is commonly used to diagnose and treat various gastrointestinal conditions, such as acid reflux, ulcers, polyps, and cancer. During the procedure, the endoscope is inserted through the mouth or anus, allowing the doctor to visualize the internal structures of the digestive system in real-time and take tissue samples if needed. Gastrointestinal endoscopy is considered a minimally invasive procedure with low risks and is typically performed on an outpatient basis.