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The colonoscopy is a medical procedure that uses a long flexible tube to observe inside the large intestine. This test can show inflamed and irritated tissue, as well as ulcers, polyps, or any type of foreign body.

What is the colon?

The colon, also known as the large intestine , is the final part of the digestive system. It is a long, egg-shaped tube in which the body produces and stores feces.

There are a wide variety of disorders that affect the colon, including colorectal cancer, polyps, ulcerative colitis, diverticulitis, and irritable bowel syndrome.

What is colonoscopy?

Colonoscopy is a medical test that, as its name suggests, has as its main objective the diagnosis and treatment of certain diseases of the colon. The test is performed using an instrument known as a colonoscope, which is inserted through the anus and advanced to the colon; It has a video camera at the end that allows you to see the entire inside of the intestine.

In addition to the diagnosis of conditions related to the colon, colonoscopy can also be used as a treatment for some pathologies. The colonoscope has several channels into which different instruments can be inserted that allow, for example, to remove polyps lodged in the intestine.

Why is a colonoscopy performed?

The reasons for performing this medical test can be very broad and diverse.

Colon cancer

One of the most frequent reasons for requesting a colonoscopy is colon cancer screening , especially in people with a family history of this type of tumor, as well as in those over 50 years of age.

Colon cancer develops when various malignant tumors form in the lining of the large intestine. The most common symptoms are: constipation , feeling that the intestine does not empty completely when it is evacuated, blood in the stool that may be bright red or black, abdominal pain and fatigue .

In the vast majority of cases, this type of cancer begins with a set of benign cells called adenomatous polyps. As time passes, these polyps can become malignant. Generally, they do not cause any symptoms at first. That is why colonoscopy is so important for the diagnosis and removal of benign polyps.

Blood in the stool

Another reason why a colonoscopy is usually requested is the presence of blood in the stool .

In the vast majority of cases, bleeding is not due to any serious cause; however, consultation with your doctor is always essential. If the blood is tarry and causes the stool to turn blackish, the causes can be very diverse, such as bleeding ulcer in the stomach, gastritis or trauma.

In the event that the blood present in the stool is bright red, it may be due to certain diseases such as hemorrhoids , anal fissures or diverticulosis.

Inflammatory bowel disease

Colonoscopy is also done to diagnose certain inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis.

  • Crohn’s disease: it is a chronic inflammatory process of the intestinal tract. Some of the symptoms of this ailment are colic, abdominal pain, diarrhea, weight loss for no apparent reason and abdominal bloating.
  • Ulcerative colitis: is a condition that causes inflammation and ulcers in the outer membrane of the rectum and colon. The symptoms of ulcerative colitis are: tiredness and fatigue, loss of appetite, rectal bleeding, and joint pain.


If a patient suffers from any of the following pathologies, colonoscopy is not a recommended test for him.

  • Irritable colon
  • Hypotension
  • Very serious bleeding disorders
  • Second and third trimesters of pregnancy: As   a general rule, colonoscopy is a test that should be avoided during the gestation period. However, it can sometimes be requested; in these cases, it is important that it be performed with the least possible sedation. As for breastfeeding, the truth is that there is no type of contraindication with the performance of this test.

How it is performed?

Next we will explain in detail how the colonoscopy is performed.


As we have pointed out, the purpose of colonoscopy is to observe the entire colon. Therefore, in order to perform the test correctly, it is essential that the colon is completely clean . The preparation period begins one to two days before the procedure.

It is the doctor who indicates the steps to follow; the patient must take laxatives, either by mouth or through enemas. In addition, 48 hours before the test you should start a diet very low in residues , without the consumption of certain foods such as vegetables or potatoes. 12 hours before performing the colonoscopy, the patient must start a liquid diet.

You may also be interested in:   Crohn’s Disease

It is important to follow these instructions exactly. Otherwise, the doctor may be forced to stop the test.


The colonoscopy lasts between 30 and 45 minutes. However, the time may be longer if some type of polyp or foreign body is detected that requires its removal or a biopsy.

The test is carried out by a doctor who specializes in the digestive system. First, he takes an IV in the arm, through which a sedative drug is administered ; in this way, he feels relaxed during the colonoscopy.

Next, the patient must lie on a stretcher lying on his left side; the knees should be bent towards the chest. To begin the test, the doctor performs a digital rectal examination to explore the anal opening ; It is practically painless, although in some people it may cause slight discomfort.

Once the digital rectal examination is performed, the colonoscopy itself begins. The doctor inserts the lubricated colonoscope through the anal opening, a flexible tube between 122 and 183 centimeters long , which advances to the colon. Thanks to the camera that the colonoscope has integrated into one of its ends, the doctor can see the interior of this area of ​​the digestive system from his screen in real time.

This is a painless test , although the patient may feel some abdominal cramps. It is also common to feel an urgent need to defecate or pass gas; It is completely normal, so do not feel uncomfortable. It must be taken into account that air is introduced through the colonoscope to relax the colon and thus facilitate its exploration. During the test it is best to breathe slowly and deeply in order to relax the muscles of the abdomen.

If during the colon exploration the doctor observes any type of foreign body, such as polyps, he must proceed to remove them; For this, it incorporates tools such as micro-forceps or micro-scissors in one of the channels of the colonoscope. In the same way, if you suspect a possible tumor, you can take advantage of the test to take samples for a biopsy.

After the colonoscopy is completed, the colonoscope is carefully removed, creating a great sense of relief for the patient, and the anal area is cleaned. The patient should be observed between one and two hours while he recovers from the effect of the sedative .

During the twelve hours after the test, it is not advisable to drive or operate any type of dangerous machinery. It is the doctor who must indicate when you can start your normal activity and what diet you should follow during the following days.

Possible complications

Colonoscopy is an extremely safe medical test. The side effects are very strange, they occur very rarely. During the test, the patient may feel some abdominal discomfort , although very slight because sedatives and analgesics are previously administered.

Once the procedure is finished, it is common to feel drowsy and fatigued for a few hours, as well as abdominal distension. In addition, if during the colonoscopy the doctor has removed one or more polyps, or has taken samples for a biopsy, during the days following the test the presence of blood in the stool is common.

Complications of a colonoscopy only occur when the colonoscope damages the surface of the mucosa , causing rectal bleeding.

Result of colonoscopy

Colonoscopy is a medical test that allows the entire intestine to be explored , in such a way that it allows diagnosing a large selection of pathologies. Once the colonoscopy is performed, the patient writes a written report detailing the potential findings, such as polyps or foreign bodies.

If the doctor has taken samples for a biopsy, they must be studied and analyzed under a microscope; a procedure performed by a pathologist and for which a report is also made.


Colonoscopy is one of the most comprehensive medical tests that exist; allows the detection of a large selection of pathologies of the large intestine . In addition, in the case of polyps, it allows them to be removed so that they do not become malignant and lead to colorectal cancer.

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Hello Readers, I am Nikki Bella a Psychology student. I have always been concerned about human behavior and the mental processes that lead us to act and think the way we do. My collaboration as an editor in the psychology area of ​​Well Being Pole has allowed me to investigate further and expand my knowledge in the field of mental health; I have also acquired great knowledge about physical health and well-being, two fundamental bases that are directly related and are part of all mental health.

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