• Reference Number: HEY1635/2025
• Departments: Endoscopy
• Last Updated: 30 November 2025

Introduction

This leaflet has been produced to give you general information about your procedure. Most of your questions should be answered by this leaflet. It is not intended to replace the discussion between you and your doctor but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team caring for you.

The aim of this booklet is:

• To explain what capsule endoscopy is
• To explain what happens on the day of the test
• To tell you what preparation is required
• To remind you about what was discussed at the pre-assessment appointment.

What is Small Bowel Capsule Endoscopy?

You have probably been troubled by some symptoms. Following discussion with your doctor you have been advised to have a small bowel capsule endoscopy.

Capsule endoscopy (pill camera) is a test which looks for abnormalities in the small bowel.

The capsule is the size of a large vitamin pill and consists of a tiny camera, battery, light source and wireless transmitter. As the capsule moves through the gastrointestinal tract, images are transmitted to a data recorder worn on a belt outside your body. The data is transferred to a computer for interpretation. The capsule is then eliminated in your stool and is not used again.

Why do I need a small Bowel Capsule Endoscopy?

The small bowel is part of the gastrointestinal tract between the stomach and the large bowel.  It is small in diameter and is between 3 to 5 metres long. It cannot readily be reached by upper endoscopy or colonoscopy.

The most common reason for capsule endoscopy is for unexplained anaemia (iron deficient anaemia) or intestinal bleeding when conventional endoscopy has failed to find the cause. It is also used for detecting Crohn’s disease, polyps, ulcers and tumours of the small intestine.

How is the test done?

You will be asked to swallow the capsule after reduced food intake since day before. The capsule starts taking the photographs which are sent by a transmitter through to a belt you wear around your waist. From there the images go to a data recorder (pocket sized computer) which is carried around in a shoulder bag.

The whole process can take anywhere between 2 and 10 hours, but everyone is different. The pill camera is given in the morning. You will be asked to be as mobile as possible for 20 minutes, and you may then be told you can go home. In some cases, the staff will check the position of the pill camera on the data recorder. If it is still in your stomach, you will be asked to walk around for another 20 minutes.

Some people have slow gastric (stomach) emptying, which can cause the capsule to be retained for prolonged time in the stomach.  If this is the case with you, we may give you medication to increase the movement in your stomach. If this is unsuccessful it may be necessary to place the pill camera in the first part of your small bowel using an endoscopy. This will only be done if it is essential and after discussion with you first.

After checking the capsule position, you may either go out for the day, use the hospital as your base or go home.

Depending on what you choose to do you will be given instructions on when you can drink and eat and what to do regarding the equipment.

Once the procedure is finished the images are downloaded from the data recorder onto a computer and converted into a video of the whole small intestine. The video is reviewed by a nurse and/or a doctor, and a report of the findings will be sent to the Consultant who requested the test. It is their decision regarding further treatment and follow-up arrangements.

Can there be any complications or risks?

There is a small risk that the procedure may need to be repeated if the pill camera has not examined the entire small bowel. This may be the case if the small bowel isn’t clean enough to see or the camera moves through the small bowel too quickly or too slow. The risk of incomplete examination can happen in up to 17 in 100 procedures.

The most serious risk is the failure of the pill camera to pass through the small bowel for more than two weeks. If this happens you might require further treatment such as anti-inflammatory medication (for Crohn’s disease), endoscopic procedure or surgery to remove the capsule. This may happen because the small bowel has a narrowing or blockage that the pill camera cannot pass through. The risk of retention is around 1 to 2 patients in 100 procedures (1 to 2%).

If there is any suspicion, you may have a narrowed bowel then a patency capsule may be used first. This is a dissolvable dummy pill that is swallowed to check that the small bowel is passable. If you require a patency capsule, further information will be given to you.

There is also a very rare risk of capsule aspiration (cause choking or entering the lungs) while patients are attempting to swallow the pill camera. If this happens and you are unable to cough it out the staff will act very quickly to help you.

What are the alternatives to Capsule Endoscopy?

There are several methods for evaluating the small bowel, including:

• Push enteroscopy (using a long flexible endoscope)
• Radiological small-bowel follow-through studies
• MRI enterography

These tests may not be the right one for you or may have already failed to find the cause which is why capsule endoscopy has been recommended for you.

How do I prepare for the…?

Please read the information leaflet. Share the information it contains with your family (if you wish) so that they can be of help and support. There may be information they need to know, especially if they are taking care of you following this examination.

You will have a pre-assessment appointment some time before you have the procedure to make sure you understand what will happen before, during and after the capsule endoscopy so that you can make an informed choice as to whether or not you consent to the procedure.

The nurse will have taken a medical history and documented your medication. They will have discussed briefly the steps you need to take in preparation.

In certain cases, bowel prep may be needed. This involves taking a specific laxative the day before the procedure to help clear the bowel. If this is the case for you, you will be informed and given additional instructions.

7 days prior to the procedure please try to eat a low residue/low fibre diet and avoid high fibre foods such as the following:

• Raw fruit or other vegetables, skins, pips
• High fibre cereals
• Salads, mushrooms, sweet corn
• Nuts/seeds
• Wholemeal bread, pasta, rice
• Also avoid red meat, pink fish

The day before the procedure

Have a light breakfast avoiding the above foods. Following this you cannot have any solid food. You should drink plenty of clear fluids such as:

• Tea or coffee (sweetened to taste but no milk)
• Fruit squashes but not blackcurrant
• Water
• Clear soups (OXO, Bovril, clear chicken broth etc – strain the soup first)
• Clear jelly (but not strawberry, raspberry or blackcurrant)
• Isotonic drinks – sports drinks

It is advisable to drink a variety of sweet and savoury drinks to avoid developing a headache.

Please drink water only from 9.00pm up until midnight then stop drinking fluids. However. if you wake in the night and are thirsty a small drink of water is acceptable.

You will be able to drink and eat the next day once the procedure has started.

Medication

You will have been advised at the pre-assessment of any medication that should be stopped prior and when to stop it. Examples below:

Medications that should be stopped 7 to 10 days before the examination are:

Iron tablets.

Medications that should be stopped 5 days before the examination are:

Codeine, Morphine, Buscopan, Mebeverine, Loperamide, Imodium.

Medications that should ideally be stopped 4 weeks before procedure are:

Medications such as Mounjaro, anti-inflammatory medications such as Diclofenac, Naproxen or Ibuprofen.

The pre-assessment nurse will discuss any you are unable to manage without and advise accordingly. Your GP should be able to suggest alternatives if required.

Patients with diabetes

Please contact your diabetes specialist or GP for advice on adjusting your diabetes medications and insulin.

What will happen?

Before you arrive at hospital

Do not eat or drink anything, except essential medication with a sip of water. Medication must be taken before 6.00am. Alternatively you can take your medication 2 hours after swallowing the pill camera which is when you will be allowed clear fluids again.

Clothing: please wear a thin, loose-fitting top so the belt can go over the top. Please wear 2-piece clothing (not a dress).

When you arrive at the hospital

Please go to The Digestive Diseases Building, which is off entrance 1, Castle Hill Hospital.

A nurse will go through the paperwork and answer any questions you may have. If you have not already signed your consent form you will be asked to do so before commencing the procedure. A copy of the consent form will be offered to you. If you have any questions or concerns, please feel free to ask/discuss.

• Blood pressure and pulse will be checked.
• The pre-assessment form will be briefly revisited to ensure that information is up to date and correct.
• Allergies will be confirmed.
• A sensor belt will be fitted around your waist and attached to the data recorder via a cable. The data recorder is in a pouch with a shoulder strap, and you will carry that around for the duration of the procedure.
• You will be offered two cups of water which contain Simethicone (Infacol) – (this is to stop bubbles forming) and asked to swallow the capsule which is the size of a large vitamin pill. It will be flashing when you swallow it.
• You must not have anything to drink until at least 2 hours after swallowing the capsule camera (you will be informed when this is).
• After 2 hours you may drink clear fluids (with your regular medication if necessary).
• After 4 hours you may take a light lunch.
• During the day, you are free to use the hospital as a base, but you will be allowed to leave the hospital, go home or go to work. Depending on where you live you can choose to keep the equipment in place until the battery dies in the data recorder (there is a blue flashing light on the top which stops flashing when battery ended). You can then take it off and return it to the endoscopy unit the following day. If you choose to stay on site or live locally, the staff will discuss a time to return to the endoscopy unit. A member of staff will check if the capsule has arrived in the large bowel and take it off.

You can return to normal activities straight after the test is complete.

What happens to the capsule camera?

The pill camera is designed to be disposable. It should pass out naturally in 24 to 48 hours. It flushes down the toilet.

WE DON’T WANT THE CAPSULE CAMERA RETURNED TO US!

If you have not seen the pill camera in 2 weeks, please contact us and we will organise an X-ray to look for retained capsule. The ward staff will give you a discharge sheet with numbers on.

If you develop abdominal pain or sickness after swallowing the capsule camera, you may have developed a blockage of your bowel. Please contact us.

If it is outside normal working hours, then please contact the A&E department or emergency GP.

If a doctor has booked an MRI scan for you, you should not have an MRI scan until you are sure that the capsule has passed through your body.

What happens afterwards?

After the examination, images are downloaded from the data recorder to a computer. At least 50,000 pictures need to be reviewed which takes time. A report is generated and will be sent to the consultant who referred you. They are responsible for letting you and your GP know the results and organising treatment and/or follow up appointments.

Should you require further advice on the issues contained in this leaflet, please do not hesitate to contact the Endoscopy Unit on Tel: 01482 622065.

General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

• you must be able to give your consent
• you must be given enough information to enable you to make a decision
• you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.