Capsule endoscopy

What is it, and what is it for?

A capsule endoscopy test is a camera test of the small bowel.  The single use camera is the size of a vitamin pill, and after swallowing takes an 8 hour video of the stomach and small bowel as it slowly passes through.  It then passes naturally in the stool.  The images are picked up on a small data recorder which is worn for the duration of the test.  They are then downloaded and reported.  The test is particularly useful in cases of unexplained iron deficiency anaemia, or when small bowel inflammation (such as Crohn’s disease) is suspected.

What are the alternatives?

Contrast x-ray of the small bowel (‘barium follow through’) or small bowel magnetic resonance imaging (‘MRI’) can pick up obvious abnormalities within the small bowel but may miss more subtle problems.  Capsule endoscopy is the most sensitive test for detecting subtle inflammation or vascular lesions in the small bowel.

Is there anything I need to do before the test?

It is very important that the stomach and small bowel is clear of food prior to the test.  Patients should have fluids only on the afternoon and evening prior to the test and then should have nothing further from midnight until they attend the hospital for the procedure.  Iron tablet should be stopped 1 week prior to the test.

What will I feel during the test?

Having swallowed the capsule you should not experience any symptoms as the camera slowly passes through the small bowel.  You will be able to leave the hospital for the day, and return just before 8 hours has passed for the data recorder to be removed.  From 2 hours after swallowing the capsule you will be able to drink clear fluids, and you can have a light snack at 4 hours, but should not eat anything further until the end of the test.

What happens after the test?

After the data recorder has been removed you can go home.  You can eat and drink normally.

Are there any risks?

Capsule endoscopy is a very safe test.  In rare circumstances the capsule can get stuck upstream from narrowings (‘strictures’) within the small bowel – this is called ‘capsule retention’.  If it is suspected that you might be at risk of this you may be given a dummy capsule (‘patency capsule’) some days before the test to ensure that the real capsule will pass.  If the capsule is retained, it can pass by itself after some days but on occasion may need to be removed endoscopically or even surgically.