116 Medical Terminology: Mastering the Basics Endoscopy An endoscopy (ĕn-DŎS-kō-pē) is a procedure in which an endoscope is used to examine internal body organs and structures (Figure 3.11). An endo- scope is a flexible, fiber-optic instrument that contains a magnifying lens and a light source. It may also be equipped with a tool for removing tissue to be examined for signs of disease. The endoscope is inserted through an existing opening, such as the mouth or nose. Esophagoscopy (ē-SŎF-a-GŎS-kō-pē) is examination of the esophagus with an esophagoscope (ē-SŎF-a-gō-skōp). If the endoscope passes farther into the stomach, the procedure is known as a gastroscopy (găs-TRŎS-kō-pē). If the endoscope is manipulated into the duodenum, the procedure is called an esophagogastroduodenoscopy (ē-SŎF-ă-gō-GĂS-trō-dū-ŏ-dĕ-NŎS-kō-pē), or EGD. Endoscopic examination of the large intestine involves inserting the endoscope through the rectum. If the scope is passed through the rec- tum into the sigmoid colon, the procedure is called a sigmoidoscopy (sĭg-moy-DŎS-kō-pē). Endoscopic examination of the entire colon is called a colonoscopy (kō-lŏn-ŎS-kō-pē). Stomach Duodenum Endoscope Figure 3.11 Endoscopy involves examination of internal body organs and structures with a flexible, fiber-optic instrument called an endoscope.