An endoscopy is a procedure that uses a flexible tube called an endoscope to examine structures inside the body. The procedure may be performed in either a hospital or a clinic setting. During a gastrointestinal (GI) endoscopy, a physician inserts the endoscope into a patient’s mouth or anus. A camera attached to the tube creates images that reveal the presence of irritation and inflammation, as well as abnormal features, such as tissue growth or ulcers.

An upper GI endoscopy passes the endoscope through the patient's throat to provide a view of the esophagus, stomach and duodenum. Some other types of endoscopies that examine the upper GI tract include:

• Esophagoscopy. Examines the esophagus.
  
  
• Gastroscopy. Examines the stomach.

An endoscopy that passes the endoscope through a patient’s anus provides images of the anus, rectum and lower large intestine, and is called a colonoscopy. Some other types of endoscopies that examine the lower GI tract include:

• Anoscopy. Examines the anus.
  
  
• Sigmoidoscopy. Examines the lower part of the large intestine (sigmoid colon), the rectum and the anus.

Endoscopies provide images that other tests cannot, and in many cases endoscopy is superior to other imaging techniques such as traditional x-rays.

A physician may use an endoscopy as a tool for diagnosing possible disorders in the digestive tract, including disorders of the esophagus, stomach, small intestine, large intestine, anus, rectum and colon. Symptoms that may indicate the need for an endoscopy include swallowing difficulties, nausea, vomiting, reflux, bleeding, indigestion, abdominal pain, chest pain and a change in bowel habits. In some cases, a physician may use the endoscopy to obtain tissue samples for biopsy in a laboratory. In other cases, a physician may use the endoscopy to remove abnormal tissue such as polyps.

A GI endoscopy may take between 10 and 60 minutes, depending on the type of procedure. Patients typically remain awake for the procedure, but may be given a sedative or anesthetic to reduce any unpleasant sensations that may accompany an endoscopy.