Colonoscopy is an exploration that allows direct visualization of the entire large intestine (colon) and also, if necessary, the final part of the small intestine (ileum).

A rectal examination is performed and a colonoscope is introduced through the anus, which is a flexible tube with a chamber at its end. The segments that make up the colon (rectum, sigmoid, descending colon, transverse colon, ascending colon, and blind) are progressively visualized. To visualize the intestine it is necessary to introduce air (CO2) and the device has light and camera at its distal end Which allows you to see the walls of the colon.

The colonoscopy can be used for the following reasons:

  • It is the best study to detect colon cancer. In turn, it can detect polyps that must be extracted for study (biopsy or endoscopic polypectomy). The search and removal of colon polyps has proven to be extremely effective in preventing colon cancer.
  • In low digestive bleeding, it allows to detect its cause and frequently treat it. Identifies diverticula, angiodysplasias, tumors, rectal fissures and hemorrhoids with active bleeding.
  • Many of these lesions may be treated (therapeutic) with vasoconstricting substances injection, clip application, argon plasma coagulator (APC).
  • Used as a diagnosis of inflammatory bowel disease including SITC and Crohn's Disease
  • Abdominal pain, changes in stools, or weight loss
  • In chronic diarrhea, biopsies can be taken to look for microscopic colitis.
  • Follow-up of a previous finding, such as polyps or colon cancer
  • Inflammatory bowel disease (ulcerative colitis-SITC and Crohn's disease

What is a therapeutic colonoscopy?

It is one in which you have to carry out some kind of SPECIAL PROCEDURE.

This is done through a channel of the endoscope are introduced certain types of clips or handles that allow, for example:

  • Resecting polyps (polypectomy or mucosectomy)
  • Hemorrhoids Endoscopic Ligature
  • Dilations.

With therapeutic colonoscopy it is possible to avoid many surgical procedures.


How the colonoscopy is performed

  • The patient should change his clothes, he should not have earrings chains, watch or any other accessory that annoys him during the examination.
  • If you have removable dentures you should remove them.
  • You will move to a stretcher. You will lie on your left side with your knees bent toward your chest.
  • An intravenous line is taken to give medication into the vein to help you relax and feel no discomfort. . It is not a general anesthetic given that the patient wakes up quickly and breathes on his own.


  • Prolonged or persistent bleeding from the biopsy site or polyp removal sites.
  • Perforation or rupture of the colon wall that requires endoscopic or surgical repair.
  • Infection requiring antibiotic therapy (very rare).
  • Reaction to sedatives, which causes respiratory, cardiac, or low blood pressure problems.

Pre-patient preparation

  • Complete colon cleansing is required, ie no feces. If this cleaning is not done correctly the study will not be of much value, since the doctor has difficulty visualizing the colon and can overlook a problem that needs treatment. For more information, see the Pre-Colonoscopy Preparation documentation.
  • If the patient should take any medication, he can do it after the test. If the test is in the afternoon and the patient should take some medication it can be done in the morning.

And after the colonoscopy?

It is advisable not to leave alone, not drive or perform activities that require concentration until recovered.

After the test, the patient will feel drowsy for a while. You may have a headache or feel bloated, but this is common after a colonoscopy. You can remove gases.

The patient may eat normally after the examination, only if a therapeutic procedure has been performed should he have a special diet if the doctor indicates.