Colonoscopy (colonoscopy) is a low-risk but not particularly pleasant examination for which the patient must be carefully prepared. Nevertheless, colonoscopy remains one of the most important examinations in cancer screening. Virtual colonoscopy (CT colonoscopy) has been available for several years as an alternative to conventional colonoscopy. In this article, you will learn everything about the implementation, preparation, and advantages and disadvantages of the two examination methods.
What is a colonoscopy?
When colonoscopy is mentioned, it usually refers to colonoscopy (colonoscopy). Colonoscopy (colon=the intestine; scopein=to see), which can visualize the inside of the rectum, colon, and the last part of the small intestine, is one of the most common examinations in the search for tumors of the colon. Colorectal cancer is the second most common cause of cancer death in Germany. According to figures from the Robert Koch Institute, approximately 32,000 men and almost 26,000 women were diagnosed with colorectal cancer in 2016. The relative survival rate over ten years was around 60 percent. However, if detected early enough, the disease is completely curable in almost all cases. In addition to colonoscopy, there is the option of having a small bowel examination (enteroscopy) performed. This is performed if there is a suspicion of bleeding in the gastrointestinal tract or a tumor-related narrowing in the small intestine. Compared to the large intestine, which is only about 1.5 meters long, the small intestine is about four meters long. Therefore, small bowel endoscopy is more complicated.
Preparation for a colonoscopy
In order to perform a colonoscopy, some preparations are necessary in advance – both by the physician and especially by the person concerned:
- Blood test: part of the preparatory phase of the procedure is to get a current blood count and check for clotting. Medications may need to be discontinued or replaced for a short time.
- Bowel cleansing: A prerequisite for a successful colonoscopy is a clear view of the intestinal mucosa. For this purpose, the intestine must be completely emptied beforehand. This takes place through the use of laxatives as well as the renunciation of special foods.
Eating before the colonoscopy
The diet before a colonoscopy is designed as follows: No later than three days before the examination, all fiber and plant seeds, including whole grains, raw vegetables, bran, soft fruits, must be avoided. Iron supplements and aspirin should also not be taken now. On the day before the examination, a light breakfast is usually allowed in preparation for the colonoscopy. Afterwards, only clear liquids should be consumed. In addition to water, these include, for example, juices without fruit pulp, black coffee, broth or tea. On the day before the colonoscopy, the bowel is also emptied by a special laxative that is taken three or four times, depending on the product. Once the bowel is completely empty, only clear water should be drunk.
Colonoscopy: sedative or anesthesia necessary?
Whether or not a sedative should be given, the doctor and patient must clarify in the preliminary discussion. Some physicians generally recommend that the patient be sedated during the examination; in other cases, this aspect is addressed by the patient himself. Anyone who is generally anxious about medical examinations should definitely make this point a topic of discussion during the preliminary consultation. Anesthesia is not usually used for colonoscopies. However, a short anesthetic (sedation) is usually possible in consultation with the physician. High blood pressure or cardiac insufficiency are in any case a reason for sedation. Since a few days always pass between the consultation and the examination, relaxation exercises and meditation are also a good way to relieve any anxiety and tension.
Shortly before the colonoscopy
Immediately before the examination, the patient is given an indwelling venous cannula. A sedative or pain reliever may be given through this access; in the rare event of a complication, this also allows emergency medications to be administered without delay. In addition, the bowel is immobilized before the procedure with the help of medication so that the natural bowel movements do not interfere with the examination.
Procedure of colonoscopy
During the examination, the patient lies on the left side. With the help of a lubricant, the colonoscope, a flexible tube approximately 12 mm thin, is advanced through the anus into the intestine. The colonoscope is flexible and can be controlled from the outside. A light source and a camera are integrated in the head of the tube. The devices are usually equipped with a video camera, so that one can follow the internal intestinal image via the monitor. Attached are usually printers and video recorders for documentation. During the examination, air is pumped into the intestine so that the empty intestine unfolds and all wall structures are clearly visible. An irrigation and suction at the end of the device also ensure good visibility. Adjusting wheels at the rear end of the colonoscope allow the front end to be bent in different directions. This makes it possible to determine the direction of the instrument as it is advanced, and at the same time to view the bowel wall closely around its entire circumference. At the same time, tissue samples can be taken through a working channel for further examination, or any polyps (benign precancerous growths) can be removed immediately without the need for further surgery. This procedure is also known as intervential colonoscopy.
Duration and follow-up
Usually, the procedure is performed in the morning. The duration of a colonoscopy is 30 to 45 minutes. Resting after the procedure is a given, as is not being allowed to drive afterward – especially if sedative medications have been administered. As soon as you feel fit enough, eating is allowed as normal after the colonoscopy.
Does health insurance cover the cost?
Since October 2002, colonoscopy has been part of the health insurers’ benefits catalog as a preventive examination. According to this, every woman from the age of 55 and every man from the age of 50 can have a colonoscopy performed as part of cancer screening. As a preventive examination, colonoscopy can be performed twice at intervals of 10 years. However, only a few people voluntarily undergo this unpleasant and painful examination. Alternatively, therefore, a stool examination can be claimed every two years at the expense of health insurance.
Alternatives to colonoscopy
Since the performance of conventional colonoscopy is perceived by many patients as unpleasant or even painful, there are now different alternatives to colonoscopy. These also have advantages and disadvantages.
Virtual colonoscopy
For several years, it has been possible to convert image data from a computer tomograph into three-dimensional views that look very similar to images from an optical endoscope. All viewing angles and directions are possible that are not adjustable with an optical endoscope. During the examination, the patient must hold his breath for about 20 seconds. During this time, his abdominal cavity is scanned with the help of a computer tomography device using X-rays. This device produces extremely fine two-dimensional cross-sectional images of the inside of the body and displays the tissue structures of the organs layer by layer. In this way, any polyps or tumors present can be found. However, similar to a conventional colonoscopy, air is pumped into the intestine during a virtual colonoscopy. In addition, the intestine must be completely emptied. An adapted diet as well as the intake of laxatives is therefore also necessary here. In addition, it is not possible to take samples from the intestine or remove polyps, as is the case with conventional colonoscopy. Long-term experience with the use of virtual colonoscopy is currently still lacking. The costs of a virtual colonoscopy are only covered by statutory health insurance in exceptional cases. They range from about 300 to 500 euros.
Colon capsule colonoscopy
The mini capsule is no larger than an antibiotic tablet. It has a miniature camera that delivers two images per second from the intestine via radio. Attached to the outside of the body is a recording device that records images from the entire digestive tract. This video recording is analyzed by a physician. The capsule is taken by the patient in the morning (on an empty stomach) just like a tablet. Afterwards, nothing should be eaten for three hours. The capsule itself remains in the stomach for about one to two hours and usually takes 90 minutes to pass through the small intestine.It leaves the body naturally via bowel movement after about 10 to 12 hours. The capsule endoscopy examination is performed on an outpatient basis. The patient can go about his daily work without any problems, there is no physical impairment. Capsule colonoscopy has not yet been as well studied in terms of its reliability as conventional colonoscopy. As with virtual colonoscopy, it is not possible to remove polyps or take tissue samples. The costs for a capsule colonoscopy are usually not covered by health insurance. They amount to approximately 1,000 euros.
