Preparation
The extensive preparation for a colonoscopy includes the examination of the blood. Here it can be determined whether there is an inflammation and whether the coagulation is in order, or whether any medication has to be discontinued. Since the intestinal mucosa must be assessed during a colonoscopy, it is necessary to have a clear view of it.
For this purpose, the bowel must be completely emptied in advance, which is achieved by adjusting the diet and taking a laxative. About three days before the colonoscopy, care should be taken to avoid foods containing grains, such as muesli, wholemeal bread, grapes or kiwis. About 24 hours before the colonoscopy, no more fibre should be consumed, i.e. no foods that are difficult to digest or flatulent.
After lunch, no further food should be eaten. Only tea, water, meat or vegetable broth should be drunk. Food must also be avoided in the evening.
Instead, you must start taking the laxative solution. To do this, two to three litres of a special solution must be drunk in about 90 minutes, which takes effect about one to two hours after drinking. In the morning of the colonoscopy, a comparably large amount of this solution must be drunk again and food must be avoided.
Which laxative is used here and how much of the solution exactly has to be drunk is decided by the treating doctor. In preparation for a colonoscopy, it is also necessary to decide together with the doctor whether sedation, a light anaesthetic, is desired during the examination. This depends on the patient’s condition, as it is usually not medically necessary.
If sedation is desired, the patient should arrange in advance for an escort to accompany him/her home after the examination and arrange for transport. This is because even after a light anaesthetic it is not permitted to drive a vehicle in the following 24 hours. The preparation also includes placing an indwelling venous cannula, i.e. an access to the patient’s blood system to inject any sedatives or other medication that may be required.
In general, drinking directly before a colonoscopy is not allowed. In order to prepare the intestine perfectly for the colonoscopy, some things have to be taken into account from about 24 hours before the procedure. Only clear liquids may be consumed.
These include water and tea, for example. Laxatives are also included. If you feel hungry or hypoglycaemic, you can also drink a lemonade.
You should avoid milk, cream and juices. If necessary, fruit juices without fruit pulp are permitted. You may drink as much as you like the day before.
On the day of the colonoscopy, you should follow the instructions of the doctor treating you. As a rule, drinking is allowed. As far as laxatives for a colonoscopy are concerned, you can choose between numerous preparations with numerous active ingredients.
Depending on the active ingredient, they have different mechanisms of action and are called laxatives in the technical language. They are also available in many different forms. Laxatives are available in tablets, powder, granules, drops and suppositories.
Except for the suppositories, all laxatives are absorbed through the mouth into the intestines. These are drunk together with a large amount of water. The intestine is already rinsed to a certain extent by the water alone.
Some laxatives stimulate the intestines to move more. This leads to a faster emptying. Other active ingredients such as the sugars mannitol or sorbitol bind the water in the intestine.
This means that it cannot be absorbed into the body through the mucous membrane and is excreted in liquid form. Furthermore, some laxatives can stimulate the intestines to secrete water and electrolytes. Therefore, with these substances you should make sure that you drink enough liquid.
These include, for example, oils or various active plant substances contained in aloe or buckthorn. The very salty active substances such as sodium sulphate or magnesium sulphate only lead to the secretion of water. Other laxatives such as lactulose also soften the stool and thus ensure faster excretion.
