What are the main risks with gastrointestinal endoscopy?
Dr. Tan Chi Chiu discusses the common concerns patients have before undertaking an endoscopic procedure of the digestive system
Many patients have anxieties about undergoing endoscopy, says Dr. Tan. The thought that a flexible instrument is going to enter the mouth and into the oesophagus, stomach and into the intestines or up the other end into the colon, fills patients with dreadful pictures. In gastroscopy patients worry about gagging on a scope that may pass the pharynx, which is quite sensitive, on its way into the oesophagus and stomach. At the other end patients worry about pain when the colonoscope enters the large intestine and has to navigate its way through the loops of bowel. These are all very reasonable worries.
Nowadays endoscopy is done very comfortably using sedative techniques. When we sedate patients for endoscopy we use medicines that will bring about a state of relaxation and perhaps put the patient into a dream like state. Under sedation patients do not experience the endoscopy at all. When they wake up they have no memory of it and no experience of it.
When patients have to undergo a colonoscopy some bowel preparation is necessary. Patients have to drink some laxative liquids in order to purge out all the faeces so that they are very clean. Patients sometimes worry that this may feel like having food poisoning or diarrhoea. But in fact it is a relatively easy procedure where the patient merely experiences the need to go to the toilet as if it were normal and then passes the motion. As the motion becomes more and more liquid the patient can see that the colon is being cleaned out. At the end, the patient may pass what may look like water or thinly stained water. Then we know that the patient is clean enough in the colon for us to do a colonoscopy and see everything.
We also inform patients of the risks of endoscopy. Sedation is at the very safe end of the spectrum of anaesthesia and the vast majority of patients do not have any ill experience with it. Only in the rarest instances due to hyper-reactivity of the patient to the medicine or an unknown allergy, might there be some complications with sedation. We generally don’t worry about this. We also tell patients that it is possible for the endoscope that is passing through the digestive system to cause a perforation of the wall of the digestive system. This is a rare occurrence and may happen when you have a diseased part of the digestive system and possibly an inexperienced endoscopist performing the procedure.
In most instances the endoscopist ought to be very experienced and will know how to navigate his way through the digestive system without running the risk of perforation. This complication is also very rare. We also tell patients that if we have to conduct therapeutic procedures, for example removing polyps, there may be instances when such a procedure leaves the patient at risk of bleeding from the procedure site. While we take every precaution to ensure that the procedure site is safe, the risk of bleeding is still there, although it is very small and we generally don’t have significant worries about this.