Endoscopy describes many procedures that look inside the body using some type of endoscope, a flexible tube with a small TV camera and a light on one end and an eyepiece on the other. The endoscope allows doctors to examine the inside of certain tubelike structures in the body. Some endoscopes can transmit the doctor’s view to a video screen. Most endoscopes also have attachments that permit doctors to take samples of fluids or tissues for laboratory testing.

There are several types of endoscopy. Each allows the doctor to check inside a different part of the body. Upper endoscopy allows the doctor to see inside the esophagus, stomach, and top portions of the small intestine. Bronchoscopy examines the large airways inside the lungs (bronchi). Sigmoidoscopy and colonoscopy examine different parts of the lower digestive tract. Each type of endoscopy uses a slightly different endoscope with a different name — an upper endoscope for upper endoscopy, a bronchoscope for bronchoscopy, a sigmoidoscope for sigmoidoscopy, or a colonoscope for colonoscopy. Other endoscopes allow doctors to see inside the abdomen or joints through small incisions.

The amount of pain or discomfort you feel depends on the area of the body being examined. For example, sigmoidoscopy (examination of the rectum and lower colon) usually requires no pain medication, while bronchoscopy, colonoscopy, and upper endoscopy usually require a sedative.

Endoscopy procedures vary in length: 10 to 15 minutes for sigmoidoscopy, 20 to 30 minutes for upper endoscopy, about 30 minutes for bronchoscopy, and 30 to 45 minutes for colonoscopy.

What It’s Used For

Endoscopy is a common procedure used for many reasons, including:

  • Cancer prevention — Sigmoidoscopy and colonoscopy allow doctors to find and remove polyps before they become colon cancers.

  • Diagnostic evaluation of a symptom such as abdominal pain or rectal bleeding — Upper endoscopy and colonoscopy allow doctors to see organs directly. Pictures of any abnormalities can be taken. The doctor can take a sample of tissue (biopsy) through the endoscope during the procedure.

  • biopsy of an abnormal finding on chest X-ray — During bronchoscopy, the doctor can take samples of secretions and bronchial and lung tissue so the samples can be examined in a laboratory.

  • Removal of a foreign body from the upper lung airways or gastrointestinal tract


The amount of preparation needed for endoscopy depends on what part of the body is being examined. For an upper endoscopy, you will be instructed not to eat or drink for six to eight hours before the test. For sigmoidoscopy, you will do an enema before the test. For a colonoscopy, you will need to clear your bowels completely of stool before the procedure. To do this, you will need to modify your diet and will be given laxatives to use the day before the procedure. In some cases, you may be asked to use an enema the day of the procedure. Before bronchoscopy you will need to follow restrictions on eating and drinking, and take special precautions regarding your mouth and teeth. Your doctor will give you specific details.

Before any endoscopy, remind your doctor of your medical and surgical history. Tell your doctor if you have any allergies. If you are a woman and there is any chance that you might be pregnant, tell your doctor.

You will need a sedative for bronchoscopy, colonoscopy and upper endoscopy. You will not be allowed to drive yourself after the procedure because the sedative may make you less alert for the few hours immediately after the procedure. Arrange in advance for someone to drive you home.

How It’s Done

In general, you will dress in a hospital gown and lie on an examination table. Your vital signs will be monitored throughout the procedure. What type of pain medication or sedatives you receive depends on what type of endoscopy you are having.


If your endoscopy takes place in a doctor’s office, you can get dressed and leave after the procedure. However, if you received a sedative medication, a friend or family member will need to help you get home. If your diet had been restricted before endoscopy, your doctor will tell you when you can start eating normally again.

Your doctor will inform you when to expect the results of biopsies or fluid samples taken during endoscopy.


There is minimal risk that the endoscope might injure or puncture some part of your body. For more specific risks related to a particular type of endoscopy, check with your doctor.

When To Call A Professional

Call your doctor immediately if you see abnormal bleeding coming from the part of your body examined by endoscopy. Call your doctor if you feel faint, dizzy, short of breath, have palpitations or if you develop a fever, chills, severe headache or muscle aches. You doctor will tell you about other specific warning signs and symptoms to watch for, depending on the type of endoscopy you had.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.