Patency capsule – patient instructions
Read our guide below to understand what to expect from a patency test and how to prepare for your appointment.
You can also download a PDF version of this patient information by following the link on the right.
What is a patency test with a PillCam patency capsule?
It safely determines whether an object the size of the PillCam video capsule can pass through your intestine.
What does the test involve?
You’ll swallow a capsule made of dissolvable material. It surrounds a tiny Radio Frequency Identification (RFID) tag that can be detected by X-ray. If the capsule leaves your body before it dissolves, this confirms that your intestine is passable or ‘patent’ for an object the size of the capsule.
If, the capsule’s still inside your body after 30 hours, it will slowly dissolve into small pieces that can pass naturally through your intestine.
We’ll contact you the next day to discuss whether the patency capsule has passed. If it has, we’ll offer you an appointment to come back for the PillCam video capsule.
What happens if the capsule doesn’t pass?
If you don’t see the capsule in your stool after 30 hours, we’ll advise you to attend the hospital for an abdominal X-ray. This will determine whether the patency capsule is still inside your body.
If you have a narrowing of your small bowel, the PillCam patency capsule can get stuck and obstruct your bowel. This can cause pain while the capsule’s stuck, but it will ease as the capsule dissolves.
This process starts after about 30 hours, but it may take up to 100 hours for the capsule to completely breakdown. In occasional cases you may need to come to hospital for management of your symptoms. Very occasionally surgery is needed.
If you need admission to hospital for any reason within 48 hours of taking a patency capsule, please bring this leaflet to show the medical team.
If you take iron supplements, stop doing so one week before the procedure
How to prepare for your patency test
During the week before your patency test you must:
- note the frequency of your bowel movements
- start a daily laxative if you don’t open your bowels at least once a day. This will make sure the capsule passes through your body before it starts to disintegrate.
- note any irregularity in your bowel movements
- prepare a list of all medications you currently take. If you’re diabetic or have any queries contact the endoscopy department.
The day before your test you must:
- start a liquid diet from midday
- not eat or drink anything after 10pm the night before your test. (nil by mouth)
- have sips of water only for necessary medication.
On the day of your test after you’ve swallowed the capsule you must:
- not eat or drink for at least 2 hours after swallowing the patency capsule. After this time you can have clear fluids.
- return to your normal diet after 4 hours.
Patency capsule indications
The PillCam patency system is an accessory to the PillCam video capsule. It helps to verify adequate patency of the gastrointestinal tract before administration of the PillCam video capsule.
You should not have this procedure if you have:
- a swallowing disorder
- a concern for aspiration,for example, due to cognitive or neurological deficits, history of aspiration or children under the age of 8 years
- suspected or known intestinal strictures, and at increased risk for bowel obstruction
- suspected or known gastrointestinal obstruction or fistulas
You should not have an MRI scan while the capsule’s inside your body. This may result in serious damage to the intestinal tract or abdominal cavity.
The safety of this device has not been established in pregnancy.
What are the risks associated with the procedure?
These include:
- capsule retention
- capsule aspiration
- obstruction
- perforation
- mucosal injury or bleeding
- allergic reaction to capsule material or other medication given.
You may need to go into hospital for management of your symptoms.
Advice for patients with diabetes who need a capsule endoscopy
This information is in addition to the instructions you’ve received.
As a diabetic, you’re at an increased risk of developing a low level of blood sugar when you don’t eat for a prolonged period, called a ‘hypo.’ You may have symptoms such as sweating, shaking, and blurred vision.
Have additional sugary/glucose drinks at home such as Lucozade. If you think you are having a ‘hypo’, have a glucose drink or take 3 glucose tablets immediately.
Contact us
Call the Video Capsule Endoscopy Specialist Nurse on 01494 425073 from Monday to Friday, 8am to 6pm (Wycombe Hospital)
Or call 01296 315220 (Stoke Mandeville Hospital) if you have any queries or concerns.