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How Does an Endoscope Work

Sonia Nair Feb 28, 2019
An endoscope is an instrument that is used by a physician to see the inner parts of the body, for diagnostic or therapeutic purposes.
The term endoscopy usually refers to the medicinal use of an endoscope. This instrument has certain industrial applications too. However, an endoscope is mainly used in medicine, for diagnosis and treatment of medical conditions.
Before the advent of endoscopy, diagnosis of internal disorders was difficult. At that time, treatment was mainly based on the symptoms, as there was no way to examine the internal organs, except surgery. However, surgery could not be used as a diagnostic tool as it would be a waste of time and money, apart from the trauma caused to the patient.
First developed in the early nineteenth century, endoscopy is a diagnostic procedure that is used to find out disorders of the internal organs. The device used for this procedure is called an endoscope. The device may also be attached with certain tools for performing minor surgical procedures, like gallbladder removal or cauterization.

Components of an Endoscope

An endoscope is a device, which consists of a rigid or flexible tube, a light delivery system, and a lens system. In some types, an additional channel to facilitate entry of other surgical tools, is also provided. An endoscope acts as a telescope, which enables the physician to examine the internal organs and cavities.
Most of the types have flexible tubes, which contain several thick optical cables. These optic cables are made of thousands of glass or plastic strands, and are assigned to different tasks. One of the cables carries light from an outside source to illuminate the area to be inspected.
Another is attached to the lens system, which undertakes transmission of images that are displayed on a monitor (or viewed through the eyepiece). Some types are attached with additional cables to carry surgical tools, which are used by surgeons, in coordination with the images displayed.
For example, tissue samples are taken from the surface of internal organs, using these tools. While rigid endoscopes are used for minimal invasion, the flexible ones are used to pass through curves and bends to reach the destination.

Capsule Endoscopy

Capsule endoscopy [Magnetically Guided Capsule Endoscope (MGCE)] is a new technology that is said to be more efficient in examining certain parts of the gastrointestinal tract, especially the small intestine. This is totally different from conventional endoscopy.
With Magnetically Guided Capsule Endoscope (MGCE), the patient has to swallow a capsule (resembles a large pill) that has a tiny camera, a battery, a light source, and a radio transmitter. The radio transmitter sends images that are recorded in a data recorder (attached to the patient's body).
The capsule is eliminated from the body through stools. The images recorded in the data recorder are downloaded, and interpreted by the doctor. This procedure has certain drawbacks. For e.g., the capsule may get stuck in the narrow parts of the small intestine. The images could be blurred, and it may be difficult to pinpoint the areas with abnormalities.

Why is an Endoscope Used

Endoscopy is usually used for detecting disorders of the gastrointestinal tract, female reproductive system, respiratory tract, etc. The procedure may be termed differently, as per the location that has to be examined. For example, endoscopy of the small intestine is enteroscopy, whereas that of the colon is colonoscopy.
In case of ears, it is otoscopy, and endoscopy of the cervix is colposcopy. A bronchoscope is used for airways and lungs, a gastroscope is meant for gullet, stomach, and small intestine, a cystoscope is for bladder, a hysteroscope is for uterus, an arthroscope is for joints, and a colonoscope is used to examine the colon.
Apart from its use in diagnosis of diseases, an endoscope is also used for minor surgical procedures, and for treating certain medical conditions.

How Does an Endoscope Work


The preparation for this procedure may vary with the type of endoscopy. While sedation is required for some types, for others it is not needed. In some cases, the patient is advised to avoid consumption of food for a period of three to four hours prior to the procedure. Laxatives may also be given to clear the bowels, as in colonoscopy.
The patient may be asked to avoid the use of blood-thinning drugs, like aspirin, for a few days before endoscopy. Antibiotics may also be administered to prevent infection. The procedure of endoscopy is painless, though some people may experience slight discomfort and mild pain.


As the patient is ready for the procedure, the doctor gently inserts the endoscope into the body. The point of entry of the endoscope depends on the affected part, which is to be examined.
The point of entry could be the natural openings of the body, like the mouth (as in upper GI endoscopy), anus (for colonoscopy), urethra (for cystoscopy), or vagina (for hysteroscopy). If such entry is not possible, the device is inserted through a small incision made for this purpose.
The whole procedure is done very carefully, as any mistake can hurt the internal cavities and organs. The doctor guides the endoscope to the affected part, so that it can transmit images of the site, to the monitor or the eyepiece. This enables the physician to visually examine the internal parts.
In some cases, samples are collected for further examination. Tools may also be used to destroy gallstones and unwanted growths like tumors.

Pros and Cons

Usually, there is no need of a hospital stay in order to undergo an endoscopy. Normally, the time span of an endoscopy ranges between 20 to 60 minutes. However, the duration may vary with the type of procedure. You may need to take rest for up to an hour after the procedure. Endoscopy is said to be a safe procedure, and complications are very rare.
It is also associated with a very low morbidity and mortality rate. Endoscopic surgeries are minimally invasive and simple. The duration is also very less, as compared to conventional ones. An endoscope is said to be highly efficient in sensing the mucosal disorders of the gastrointestinal tract.
In some cases, infection or bleeding may develop after this procedure. Rarely, perforation of the gastrointestinal tract may occur. Damage to the internal organs and major blood vessels is another uncommon complication of endoscopy.
The infection may develop at the site, through which the endoscope was inserted. In that case, symptoms, like redness, swelling, pain, etc., may be experienced. Some of the complications are associated with improper cleaning of the endoscope.
Thus an endoscope is a very useful tool in the medical world, helping doctors to diagnose various disorders with pinpoint accuracy. Though it causes slight discomfort, endoscopy is painless and should be done if the doctor deems it necessary as part of your diagnosis.
As far as the risks and complications are concerned, you must discuss it with your physician, before undergoing the procedure.
Disclaimer: It is for informative purpose only and should not be used as a replacement for expert medical advice.