Colonoscopy A colonoscopy is a diagnostic procedure in which the inside of the colon can be inspected with a flexible endoscope. A colonoscopy is performed to gain an insight into the rectum and the colon. Indications for a colonoscopy are initially all complaints of the intestinal area that persist over a longer period of time.

These include long-lasting pain in the intestinal area, blood in the stool, a drop in haemoglobin in the blood count (this value can be an indication of bleeding, which must be ruled out in the intestine). Blood in the stool can either be visible immediately, be noticeable in the form of black, sticky stool (tarry stool) or not be visible to the naked eye at all (see: intestinal bleeding). Therefore, a so-called haemoccult test is often carried out to determine whether there is blood in the stool.

In addition, colonoscopies are also carried out for chronic diarrhoea. A further indication is the search for tumours due to suspicious symptoms. These include the typical triad of unclear weight loss (>10% of body weight within 6 months), heavy night sweats and fever (>38°C), also known as B-symptoms.

Furthermore, a colonoscopy can be performed if a chronic inflammatory bowel disease such as Crohn’s disease or ulcerative colitis is suspected. These can make themselves felt, for example, through abdominal pain and frequent diarrhoea, some of which is bloody, and often occur for the first time at a young age. In case of symptoms such as changes in bowel movement in the sense of sudden constipation (constipation) or frequent diarrhoea (diarrhoea) or a change from both, a colonoscopy should also be considered for diagnosis.

Colonoscopy as a preventive examination

A large field of application of colonoscopy is also the preventive examination. It is recommended that every patient over 55 years of age have a regular colonoscopy as a preventive measure in order to detect colon cancer or its precursors at an early stage. Like mammography or skin cancer screening, colonoscopy is paid for by the statutory health insurance companies.

Experts have agreed for some years now that the risk of developing new formations, which can develop into malignant structures in the course of the disease, increases significantly from the age of 50. However, this has not been taken into account by the health system so far and the first preventive colonoscopy, the costs of which are covered by health insurance companies at most twice within 10 years, is still planned from the age of 55. Follow-up examinations should take place every 10 years if the findings are inconspicuous.

If colon polyps were seen and removed during the examination, another colonoscopy should be performed after only 5 years. For people with family members who are or have been suffering from cancer of the colon (colorectal carcinoma), preventive colonoscopy is financed by health insurance companies in earlier years. In the case of a certain familial form of colorectal carcinoma, familial adenomatous polyposis (FAP), the first colonoscopy should be performed as early as the age of 20, as the risk of the disease is very high in this case.

Subsequently, a colonoscopy should be performed every year. Colon cancer is the second most common fatal cause of cancer in men and women, which are the most frequent causes of death in Germany after cardiovascular diseases. Detecting tumours as early as possible demonstrably improves the patient’s chances of recovery and survival.

No one is obliged to undergo the examination and everyone can decide for or against the examination after weighing the arguments. Before deciding to undergo the examination, a consultation is mandatory in Germany. In this consultation, the potential candidate is given information about the frequency of the disease being examined, the risks of the examination and what happens if a tumour is actually found.

Also, the person being examined should always bear in mind that a finding as “ill” does not always represent the final diagnosis. For many patients, an initial conspicuous examination finding turns out to be harmless in the further course of the examinations and clarifications. This is very impressive in the case of abnormal breast cancer.

With this type of breast cancer, only less than 20% of patients with this type of cancer develop real breast cancer during further examinations. However, the effectiveness of screening for intestinal cancer is very high, as intestinal cancer often develops from already existing polyps, benign growths of the intestinal mucosa, which are present and detectable years to decades before degeneration into a tumour. A high percentage of these polyps degenerate into a tumour at some point, so that the risk of developing intestinal cancer can be reduced enormously by removing them.

A colonoscopy requires a few preparations several days in advance. Since the intestine must be empty for the examination, so that you can see anything in the intestine except the remains of digested food instead of the intestinal wall. For this purpose, a laxative is prescribed the day before the colonoscopy (around 2 p.m. the day before).

This is given to the patient as a liquid to drink or as a powder which must be drunk together with a lot of liquid. As the juice is not easy to drink for many people due to its unpleasant taste, some varieties can be diluted with some fruit juice. However, this should be asked for in advance.

Many patients also report that the liquid is easier to drink when cooled. The amount is about 2 litres, which should be drunk within a time window of 90 minutes. Another litre of the fluid should be drunk in the morning before the examination.

After that, all intestinal contents should be excreted until there is only clear fluid in the intestine and only clear or slightly brownish fluid is excreted. The effectiveness of the examination depends crucially on the complete emptying and cleaning of the bowel. If the bowel is not sufficiently emptied during the examination, a post-cleaning may be necessary in the practice, which can delay the duration of the examination by several hours.

In addition to the laxative, there are a few more tips for effective bowel emptying. Approximately 5 days before the examination, one should refrain from eating high-fiber foods such as grains and fruits containing seeds, as swelling grains can clog the bowel. During the remaining days, you should fall back on rather easily digestible food such as porridge or yoghurt.

At the latest from the lunch of the previous day onwards, food should be avoided completely. If you have a sluggish bowel, you should avoid solid food before. Drinks such as fruit teas, water and clear broth are permitted during the food leave.

However, black and green tea, cola and coffee can leave stains on the intestinal wall and should also be avoided. These drinks also often prevent the patient from feeling too hungry due to the filling of the intestine. If hunger still occurs, chewing gums can also help, but these should only be chewed for a maximum of two hours before the examination.

If you are taking medication regularly, you should also discuss the intake with your doctor. Diabetics should adjust their insulin dose accordingly during the period of food withdrawal. Patients taking blood thinners should also discuss the procedure in the days before the examination, as taking them increases the risk of bleeding during the examination.

Patients taking the contraceptive pill are recommended to use additional contraception in the period after the examination, as the altered intestinal activity can alter the absorption of the active substances and the effect of the pill can no longer be guaranteed. The examination itself can be carried out on an outpatient basis in otherwise healthy patients. This means that the patient comes for the examination in the morning and can then be discharged home after a monitoring phase. Immediately after the examination everything may be eaten again, only the digestive system may need a few days to recover until it has returned to normal.