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.

An endoscopy uses a flexible tube with a camera called an endoscope to examine structures inside a patient’s body. The lining of the digestive tract is examined during a procedure known as a gastrointestinal (GI) endoscopy. During this procedure, the endoscope is either passed through the mouth to view the esophagus, stomach and most of the small intestine, or through the anus to view the anus, rectum and lower large intestine. The images provided by an endoscopy may not be available using other techniques, and endoscopic images are often superior to those of a standard x-ray.

An endoscopy will be performed by a gastroenterologist, a physician who has expertise in both GI disorders and in using an endoscope. Signs and symptoms that may cause a physician to order a GI endoscopy include bleeding, abdominal pain, difficulty swallowing and a change in bowel habits.

Endoscopy can be used to diagnose or treat many disorders of the digestive system. Some examples of such disorders include:

• Inflammatory bowel disease
• Peptic ulcers
  

  

• Diverticulosis
• Appendicitis
• Gallbladder stones
• Colon polyps
• Colon cancer
  

  

The endoscope itself is a long flexible tube with several channels that can project light on the area being examined. A camera attached to the tip of the tube allows images to be captured. Air also can be pumped through the tube to expand tissue folds, making it easier to see the stomach. Surgical instruments can be passed through the endoscope to perform surgery, and a small clipper attached to the endoscope can be used to collect a sample for biopsy.

Endoscopes range between 1 foot and 5 feet (0.30 to 1.52 meters) in length, and between 1/4 inches and 1/2 inch (0.64 to 1.27 centimeters) in diameter. Different-sized endoscopes are used to examine various parts of the digestive tract. Endoscopes can reveal the presence of irritation and inflammation, as well as features such as tissue growth, hiatal hernia or ulcers.

In some cases, a physician may discover an apparent abnormality during examination that requires further analysis by biopsy. A small clipper attached to the endoscope can be used to obtain a tissue sample that is then analyzed in a laboratory. This analysis can help determine the cause of the abnormality (e.g., inflammation, infection, cancer). Patients do not typically experience pain when the sample is removed because few nerves exist in the lining and inner walls of the digestive tract.

Gastrointestinal (GI) endoscopies are performed using one of two techniques: inserting the endoscope through the mouth to examine the upper GI tract, or inserting the endoscope through the anus to examine the lower GI tract.  

When the endoscope is inserted through the mouth, it is known as an upper endoscopy. This approach enables the physician to view the esophagus, stomach and duodenum. Also known as an esophagogastroduodenoscopy, this procedure is used to diagnose swallowing difficulties, nausea and vomiting, reflux, bleeding, indigestion, abdominal pain, and chest pain. These procedures normally take between 15 to 20 minutes. Examples of upper endoscopies include:

• Esophagoscopy. Examines the esophagus.
  
  
• Gastroscopy. Examines the stomach.
  
  
• Upper GI endoscopy. Examines the esophagus, stomach and duodenum (the first part of the small intestine).
  

  

• Enteroscopy. The small intestine beyond the duodenum is examined using a long endoscope, or enteroscope.
  
  
• Endoscopic retrograde cholangiopancreatography (ERCP). An examination of gallbladder, pancreas, and the ducts that drain into the liver. After the endoscope is inserted, a dye is passed through a thin flexible tube (catheter) inside the endoscope before x-rays are taken.

In other cases, the endoscope is inserted through the anus. This allows the physician to see the anus, rectum and large intestine. It may take from a few minutes to an hour to perform these procedures. There are three major types of these endoscopies:

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

Patients should closely follow their physician’s advice about all the preparatory measures necessary before an endoscopy. Patients usually are asked to stop eating for several hours prior to or the night before the procedure, because food that is present may obstruct the physician’s view of the digestive tract and potentially cause the patient to vomit during the procedure. Patients may also be advised to change their medication routine. For example, taking aspirin just prior to an upper endoscopy could cause false readings on some tests.

Patients scheduled to have an endoscopy of the lower gastrointestinal tract usually have to take laxatives and may be asked to undergo an enema prior to the procedure to ensure that the colon is empty of stool. They also are asked to avoid solid food for several days prior to the procedure.

The procedure may be performed in either a hospital or a clinic setting. A sedative or anesthetic may be administered intravenously prior to an esophagoscopy, gastroscopy, upper gastrointestinal endoscopy, or colonoscopy. The air that is pumped into the digestive tract during endoscopy sometimes causes discomfort, and sedation can reduce the unpleasant feeling. Some patients also may react to any anesthesia that is given. The patient’s breathing, blood pressure, heart rate and oxygen level will be closely monitored to ensure safety.

Patients who undergo an upper endoscopy may receive a spray or gargle solution with an agent that numbs the throat. This can help prevent the patient from gagging when the endoscope is inserted.

The procedure will unfold differently depending on the type of endoscopy being performed. During an upper endoscopy, patients are placed on their left side and a plastic mouthpiece is positioned between the teeth. This props the mouth open, making it easier to insert the tube. The endoscope is lubricated, and the patient is asked to swallow it. Any saliva that builds up is suctioned away with a suction tube. The physician inspects the lining of the esophagus, stomach and small intestine using high-quality images captured by the endoscope that are projected onto a monitor or viewed directly through an eyepiece. If necessary, tissue samples are removed for biopsy or foreign bodies and polyps are cut away. The procedure usually takes 10 to 15 minutes.

During an endoscopy of the lower GI tract, patients are also placed on their left side. The physician then lubricates the endoscope and inserts it into the anus. The physician studies images of the colon and rectum walls that are transmitted to a monitor and performs any necessary surgery. Patients may be asked to change position to assist the physician in moving the endoscope. The procedure usually takes 15 to 60 minutes to complete.

Following the procedure, patients who have been sedated may be asked to wait for an hour or two while their sedative wears off. These patients also should not drive themselves home.

Endoscopies are safe procedures that rarely cause complications for the patient, although in rare cases a patient may have an allergic reaction to anesthesia. However, in rare cases an endoscope may puncture the digestive tract, causing a hole (perforation) to form. If this occurs, it may require surgical repair. Pain, bleeding and infection also sometimes occur as the result of an endoscopy.

However, it is more likely that patients who experience complications will have only minor irritation or bleeding of the digestive tract.

Rare complications associated with upper endoscopies include:

• Severe irregular heartbeat
• Pulmonary aspiration (in which foreign matter enters the trachea [windpipe])
• Fever
• Breathing problems

Rare complications associated with endoscopies of the lower gastrointestinal tract include:

• Dehydration as a result of using too many laxatives or enemas
  
  
• Cardiac arrhythmias (abnormal heart rhythms)
  
  
• Bursting of combustible gases in the colon when polyps are removed
  
  
• Breathing problems

In addition, patients should contact their physician if they experience any of the following symptoms:

• Unexplained or chronic abdominal or chest pain, including heartburn
• Swallowing difficulties or pain when swallowing
• Nausea and vomiting or reflux
• Indigestion
• Weight loss (unexplained)
• Unexplained and persistent changes in bowel habits
• Abdominal pain
• Diarrhea
• Black or tarry stools or bleeding from the rectum

A new instrument, called a capsule endoscope, allows physicians to look for abnormalities in the small intestine. Patients swallow a capsule that contains a tiny camera, which transmits images of the small intestine to a recorder worn around the patient’s waist for later viewing by a physician. The camera passes painlessly in the patient’s stool.

Capsule endoscopy is used when extensive testing has failed to reveal the source of gastrointestinal (GI) disorders such as bleeding. The test can also be used to evaluate conditions of the small bowel that cause diarrhea, pain or weight loss, such as Crohn's disease.

The capsule endoscope shows promise in providing images of areas of the small intestine that are hard to reach during a conventional endoscopy. Although the procedure has been approved by the U.S. Food and Drug Administration (FDA), it is only used in a handful of medical centers across the country and is not considered to be a substitute for traditional GI endoscopy.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions related to endoscopy:

1. Which type of endoscopy is most appropriate for my condition?
   
   
2. Why is an endoscopy superior to other imaging techniques in my case?
   
   
3. What exactly will occur during my endoscopy?
   
   
4. Will I need to alter my diet before the test?
   
   
5. Are there any other lifestyle changes I should make prior to the test?
   
   
6. Will my endoscopy cause me any pain or discomfort?
   
   
7. Will I be given a sedative or anesthetic prior to the test?
   
   
8. What are the potential risks and complications of the test?
   
   
9. How long will my endoscopy take?
   
   
10. How long will it take to get the results of my endoscopy?