Colonoscopy: what is this medical test used for?

A medical diagnostic procedure that can detect various diseases.

If we hear the word colonoscopy most people know what it is talking about, and we probably react with some distress or discomfort at the thought that it may be necessary to have a colonoscopy.We probably react with some distress or discomfort at the thought that it may be necessary to have one at some point in our lives.

Although it is often considered unpleasant, it is a necessary procedure that allows us to diagnose and treat various pathologies. In this article we are going to see what a colonoscopy is, what it is used for and how it is performed.

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Colonoscopy as a medical procedure

Colonoscopy is a type of test or exploratory medical procedure in which through the insertion of a colonoscope (a tube-shaped instrument with a micro-camera at its end) it is possible to examine and evaluate the condition of the patient's colon and large intestine.

It is a type of objective examination that allows the recognition and evaluation of the state of part of the digestive system and especially the excretory, in which in addition to the visualization through the camera it is possible to obtain data through the realization of biopsies. In some cases colonoscopy is also performed therapeutically, since some instruments can be introduced through cavities in the colonoscope itself that can help, among other things, to suction or extract foreign bodies or to close small lesions.

Basic procedure

When performing a colonoscopy, first of all it is necessary that the part of the organism to be visualized is free of material that may prevent the correct analysis of the organ. For this reason, elements such as laxatives or enemas are usually used beforehand to allow the client to evacuate and not have fecal material in the colon.

Once this is done, depending on the case, it may be advisable to administer an anesthetic or analgesic in order to avoid possible pain or discomfort in the patient. The physician performs a rectal examination to check for obstructions and at the same time to dilate the anus. Then the device is placed: the patient lies on his side with his knees bent and the device is inserted through the anus.

Air is then introduced into the area to be examined in order to facilitate the examination, and finally the examination is performed.and finally the examination is performed. Depending on what is found, if there is anything unusual, the physician may decide to take samples or take other actions.

Finally, the device is carefully removed, at which time observations can also be made. It is common that, given that air has been introduced, some pain or gas may appear, which may even be expelled at the moment of the extraction of the colonoscope.

Generally, the subject usually remains under observation for a few hours until the effects of the anesthesia have worn off.

Subtypes

The procedure indicated above is the one most frequently used. However, there are several subtypes of colonoscopy.

1. Conventional colonoscopy

The most commonly used, it refers to the basic procedure described above: the colonoscope is introduced through the anus and rectum to make a tour and analysis of the inside of the colon. In conventional colonoscopy, the entire colon is examined.

2. Flexible Sigmoidoscopy or Proctosigmoidoscopy

Like conventional colonoscopy, the colonoscope (in this case sigmoidoscope) is used to visualize only a part of the colon, specifically its lower third or sigmoid. In this case, sedatives are not usually used.

3. Computerized Tomography Colonography or Virtual Colonoscopy

This type of colonoscopy is less uncomfortable and less invasive. Contrast measures are administered beforehand. A colonoscope is introduced through the rectum but without the need to enter the organism to a great extent: only air is introduced to facilitate observation. The images will be taken by X-rays from the outside.

4. Capsule colonoscopy

This type of alternative colonoscopy is one of the most recent modalities and is much less invasive than the previous ones. The patient has to swallow a small capsule with built-in micro-cameras that will send images to sensors placed in the patient's abdomen (although he/she will have previously performed a colon cleansing in order to obtain useful images). The patient does not require hospitalization or sedation. Once the capsule has been excreted, the data obtained will be analyzed.

In which cases is it used and what can it detect?

Although it is uncomfortable, this test is of fundamental importance.. It is currently one of the most effective ways of detecting diseases such as colon cancer or polyps that may degenerate into colon cancer. This extraction is also usually performed by colonoscopy. It is frequently performed in people over fifty years of age.

Another frequent reason for its use is the study of the causes of the appearance of Blood in the process of defecation or simply bleeding from the rectum. It allows to see its causes and detect diseases such as irritable bowel syndrome. In cases of persistent pain and sudden weight loss, fissures, abscesses or blockages due to foreign bodies are also visible with this technique.

Colonoscopy, as we have said, not only allows images to be taken. It is also possible to take biopsies of suspicious contents for later analysis or even to perform procedures such as cauterizations, sutures or excisions.

Risks

Although it is a very useful and necessary test, it may involve some risks.. Specifically, it can sometimes lead to perforations in the colon or intestine, causing bleeding. However, this extreme only occurs in very rare cases.

The use of techniques such as virtual and capsule colonoscopy reduce these risks, although they may not be as effective. Otras posibles molestias son la presencia de dolor abdominal y gases.

Referencias bibliográficas:

• Lieberman, D.A.; Rex, D.K.; Winawer, S.J.; Giardiello, F.M.; Johnson, D.A. & Levin, T.R. Guidelines for colonoscopy surveillance after screening and polypectomy: a consensus update by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2012;143(3):844-857.