Hi Yoke Peng,
First, you need to understand that capsule endoscopy was first designed to allow doctors to look into problems arising from the small intestine where routine endoscopy fails to reach, due to the length of the entire small bowel.
Over time, newer capsule endoscopes were developed to study the oesophagus and large intestine for cases when routine endoscopy cannot be carried out. This system powers itself and takes pictures at variable rates and wirelessly transmits the signals back to the data collector.
The doctor will then retrieve the many thousands of pictures taken and run through them quickly like a movie clip to detect any pathology in the digestive tract.
Let me start by assuring you that there is nothing to be afraid of for routine upper and lower digestive tract endoscopy. They are carried out with sedation almost all the time, making it a comfortable experience for most people. The risk of routine endoscopy is also low.
If you have a condition suspected to originate from your stomach or large intestine, I will personally advise you to consider routine endoscopy over capsule endoscopy and I am going to tell you why.
Capsule endoscopy is purely diagnostic in nature, which means it is incapable of collecting tissue samples for histological analysis when required. It cannot be used to treat any condition such as bleeding in the digestive tract, while routine endoscopes are expected to be able to do so.
As the current capsule endoscopy system is designed to be passive in its movement, it literally tumbles down the digestive tract, subjected to normal bowel movements. We are not able to control its speed of movement and direction of view. This means that we cannot stop to observe a suspicious area one second longer and cannot direct the view to any area we want to study closely.
Besides the high cost there is also the potential risk of a capsule being retained in your intestines if there is an area of narrowing in your intestine. Under that circumstance, surgery may be required to retrieve the capsule.
However, if your problem is suspected to originate from the deeper portions of your small intestine, then capsule endoscopy may be recommended as a first line, less invasive investigational tool, since routine endoscopes may not reach that area.
Do speak with your gastroenterologist in greater detail to pinpoint the most suitable procedure which suits your needs best.