What is a colonoscopy and how is it done?

Colonoscopy is a test ordered to diagnose specific diseases or scheduled as a screening test for colorectal cancer. This examination often causes a lot of stress among patients, with many being reluctant to get tested. Some patients choose not to have the examination done despite medical indications. Such an approach may significantly increase the risk of developing a serious disease, and thus can lower the chances of a full recovery. So what is worth knowing about a colonoscopy?

Colonoscopy - what is it?

Colonoscopy is an endoscopic examination of the lower gastrointestinal tract. It is ordered to diagnose diseases of the large intestine and the end part of the small intestine - it is considered one of the most effective tests for detecting early stages of colorectal cancer.

Colonoscopy - what does the examination look like?

The test itself involves the insertion of a flexible tube into the back passage which ends with a camera and a light source. This tube is known as a colonoscope and allows a gastroenterologist to get a close look at the inside of the intestines. Thus, the examination allows to exclude or confirm the presence of diseases at an early stage of their development. The colonoscope also acts as a channel through which diagnostic tools are introduced to collect biopsies. Such samples are then sent to a laboratory for histopathological and microbiological examination. Small polyps can be completely removed during a colonoscopy (this is known as a polypectomy).

Colonoscopy - preparation for the examination

Just before the examination, the patient puts on a special gown and then lays down on his/her side. In the next step, the doctor lubricates the patient's anus with an anesthetic gel and slowly introduces the colonoscope. The instrument is gradually advanced along the entire length of the colon. The camera at the end of the colonoscope allows the physician to directly examine the inner lining of the intestines - the image from the camera is displayed on the monitor during the examination. To allow for a precise examination of the intestinal mucosa, the colon has to be distended with gas that is introduced during the procedure.

Colonoscopy - is it painful?

You will likely feel some discomfort during a colonoscopy. You may feel pressure and some level of pain due to the gas distending the bowel. For this reason, colonoscopy is performed under local anesthesia and sometimes also under sedation. In the case of children, the test is performed under general anesthesia.

How long does a colonoscopy take?

A colonoscopy is a procedure that usually takes 15 to 40 minutes. In some cases, fully advancing the colonoscope through the entire large intestine turns out to be impossible (for example due to strictures in the colon). In such cases, other examinations are ordered or, if the doctor deems it so, an incomplete examination with a colonoscope will be sufficient.

How to prepare for a colonoscopy?

Proper praparation for a colonoscopy is crucial - poor bowel cleansing significantly reduces the sensitivity of the test and may mean a repeat examination is required. Before the test you have to follow a special diet and take medications that help clear the bowel.

Colonoscopy - preparation for the examination and diet

When the patient receives a referral for the examination, they should also be informed about the necessary preparation. The main recommendations include:

• One week before the colonoscopy - avoid eating grain bread, any grains, poppy seeds, linseed, stone fruit and foods that are hard to digest and cause bloating; you should give up iron preparations and avoid eating beetroot;
• 72 to 24 hours before the examination - you should follow a liquid diet and do not eat solid foods, in particular meat, bread and potatoes; alcohol, coffee and carbonated drinks should be discontinued; it is recommended to drink large amounts of still water;
• The day before - in the case of an examination scheduled for the morning, you can eat the last liquid meal in the afternoon; in the evening you should take a laxative (remember to drink large amounts of still water, preferably about 2-3 liters); in the case of an examination planned for the afternoon, the last meal should be eaten in the evening of the preceding day, and laxatives should be taken in the morning.
• 2-3 hours before - about 2 hours before the procedure do not dring any fluids.
• Immediately before the examination - you may take sedatives or anesthetics will be administered (in some institutions this service is additionally payable).

After a colonoscopy - what to expect?

After a colonoscopy, it is important to remove gas from the bowel. It is recommended to assume the same position as when passing stool - this allows for quick removal of excess gas. If this does not help with the discomfort antispasmodics may be prescribed. The relaxation of the intestines makes it much easier for air to travel to the end of the digestive system. However, if this method does not work either, the patient is fitted with a rubber tube, that facilitates the escape of gases.

Colonoscopy - why is it so important?

Colonoscopy is an examination that is associated primarily with discomfort and stress. However, it is worth chasing away any fears. Colonoscopy can allow for the early detection of colorectal cancer, a disease that can develop asymptomatically for years. Treatment of colorectal cancer diagnosed at an early stage carries a good prognosis.