How the patient experiences an endoscopy and what to look for depends largely on the type of endoscopic examination he or she is about to undergo. Some involve so much effort that the patient is put under general anesthesia for them, as in laparoscopy. Others do not require any anesthesia at all, such as endoscopy of the uterus.
In the most common form of endoscopy, gastroscopy and/or colonoscopy, the endoscope is inserted through the mouth or anus. A local anesthetic is applied to the area in question to prevent pain from irritation there. The stomach or intestines must be free of food residues, which is why the patient is not allowed to eat anything for some time before the examination and, in the case of colonoscopy, is also given laxatives.
Both examinations often take place after administration of a sedative, which reduces pain sensation and anxiety, but still allows the patient to respond to instructions (analgesia). If such a drug is administered, the patient is not allowed to drive a car or operate machinery afterwards. It is also important to ensure that the stomach is not immediately overloaded with too much food. Precise instructions on what to observe during the respective endoscopic examinations are provided by the attending physician.
New endoscopic techniques
In most cases, it is not particularly pleasant to endure an endoscopic examination, even though the devices are now quite small and flexible. But resourceful developers in medical technology are already ahead of the game: with “virtual endoscopy,” there is no need for an endoscope; instead, by combining fluoroscopic examination methods such as X-ray or magnetic resonance imaging and special computers, a virtual internal 3-D image of the organ being examined is generated. The physician can then move through the interior of the body on the screen, as in endoscopy, without actually inserting an endoscope into the patient. The disadvantage of this technique is that no tissue can be removed for examination.
In principle, virtual endoscopy is possible for any cavity of the body – air-filled spaces such as the stomach and intestines, sinuses or inner ear, and fluid-filled spaces such as vessels or bronchi. The most common is virtual colonoscopy.
Another technique for endoscopic imaging of the gastrointestinal tract that is comfortable for the patient is so-called capsule endoscopy. Here, the patient swallows a capsule containing a miniature camera, a transmitter and a battery. The camera travels through the gastrointestinal tract and sends two images per second from its camera to a receiver that the patient carries with him. During this process, he can go about his daily activities normally. After the endoscopy, the images are assembled into a “film” by the doctor on a computer. The capsule is excreted and not recycled. Another advantage of this method is that it allows visualization of the small intestine, which is largely inaccessible to other endoscopic techniques.