Procedure of a colonoscopy

Synonym

Colonoscopy, bowel examination English: colonoscopy

Definition

A colonoscopy is a diagnostic procedure in which the inside of the colon can be inspected with a flexible endoscope. Before the end of the colonoscopy, the patient’s intestine must be cleaned in order to provide the examiner with optimal visibility during the procedure. For this reason, the patient has to take medication for laxative measures before a colonoscopy.

One day before the examination, the patient usually has to drink water with Movicol or similar preparations dissolved in it, which have a laxative effect. Furthermore, he should not eat before the end of the examination. Colonoscopy is seldom performed in the hospital ward, but mostly in the endoscopic departments that almost every hospital has.

The patient is positioned on his side shortly before the procedure. In addition, a venous access (brown tube) is inserted, through which a short anaesthetic or, if complications arise, life-saving medication can be applied directly into the vein. Propofol is usually used as a sleeping pill in low doses during a colonoscopy.

The patient then falls asleep. A pulse oximeter attached to the finger can be used to monitor the patient’s heart rate and oxygen saturation during the procedure. The examiner, usually additionally dressed in a plastic apron, inserts the flexible colonoscope into the patient’s anus after a thorough examination.

Using buttons attached to the handle, the colonoscope can be rotated in all directions at its tip, similar to a snake’s head. Shortly after inserting the coloscope, air is introduced into the intestine during a colonoscopy. The reason for this is that the intestine has the property of collapsing when empty, which makes visibility very poor.

With the help of the air the intestine is unfolded. Some patients who do not want to have a short anaesthetic before the procedure describe the air intake as unpleasant to painful. The examiner now pushes the colonoscope forward bit by bit.

Initially, the focus is not on examining the bowel, but on carefully manoeuvring the endoscope through the bowel. It is important that the intestinal wall is not damaged during a colonoscopy. Constricted areas are opened by increasing the air intake.

With the help of the camera and the very powerful lamp, the current image is projected onto a monitor next to the examiner. The mobility at the tip of the colonoscope only helps to change the camera setting accordingly, however, the skill of the examiner is needed to move the colonoscope. From the outside, he can manoeuvre the examination device with left and right movements in such a way that it is advanced to the transition from small intestine to large intestine.

In doing so, it must cover a distance of approx. 1. 50 m. At the so-called Baumann’s valve (transition from small intestine to large intestine) the advancement manoeuvre is usually completed.

From now on, the colonoscope is slowly retracted and the actual colonoscopy begins. The colon walls are inspected, redness, swelling and evidence are assessed. In conspicuous areas, a wire can be pushed forward from the outside to the tip of the colonoscope.

A small pair of pliers is attached to the tip of the wire. With these pliers, the examiner can grasp suspicious areas of the intestinal wall, pull them from the outside and transport them outside. The tissue samples, also called biopsy, are then sent to the pathology department for pathological assessment.

In addition to the live image, it is also possible to take pictures with the camera. Every suspicious area must be photographed during a colonoscopy in order to be able to reconstruct the examination procedure later on. In addition to the insertable forceps, loops can also be inserted into the intestine via the endoscope, with which, for example, polyps, which are often found on the intestinal walls, can be wrapped around and removed. When the examiner reaches the bowel outlet again, the device is pulled out and disinfected. The patient usually remains in a sleeping or twilight state for a short time and is brought back to the ward.