Cytosponge/EndoSign (Capsule Sponge)


This leaflet provides you with information about a new test called Capsule Sponge. It explains:

  • What the test is and why you might need it
  • How you prepare for a test
  • What to expect when you have your test
  • What happens after the test
  • What the risks of the test might be
  • What alternatives to the test you could be offered?

Capsule Sponge alongside a range of other vitamins, Capsule Sponge is the middle capsule on a string


To help protect both our patients and staff in the changing health situation brought about by Covid-19, all patients will be screened pre-procedure. This will help us to identify any potential infection risk.

When you are booked for your procedure – you will be asked a series of questions regarding ‘red flag’ symptoms. At the same time – you will be asked to self-isolate for a period of 72 hours. You will need to maintain social distancing measures from the other members of your household and keep good hand hygiene after using shared facilities.

At the beginning of this 3 day period you will be screened for any possible Covid infection. This will be done via an oral and nasal swab and will be arranged by appointment. The result of the swab should be available before your procedure date. Following your swab you will be advised to continue to self-isolate to reduce your risk of exposure to the coronavirus. This isolation will end once you have had your procedure. You will be asked the same checklist of screening questions at booking, the day before your procedure and on admission to the Endoscopy Unit.

If you have any red flag symptoms or if you have a positive swab your referral will be deferred until it is safe to proceed.

We ask that you adhere to strict social distancing measures whilst in the department and we apologise that due to these circumstances you will not be able to bring a family member with you into the hospital. If you require an escort home – they will be asked to park outside the hospital and a nurse will take you to meet them.

The Endoscopy department takes your health very seriously and has worked hard to implement a safe pathway for patients. Any procedures on symptomatic patients will be undertaken in a separate department (or at the end of the day on a separate pathway) to ensure your safety.

What is a Cytosponge/EndoSign(Capsule Sponge) test?

This new test is being introduced in a number of areas in the NHS as it has been proven in clinical trials to be a simple, safe and effective way of diagnosing conditions related to the oesophagus (gullet).

Your GP has referred you for an endoscopy (a test with a camera to examine your gullet and stomach) to understand your current symptoms. We are evaluating the role of Capsule Sponge as an innovative alternative to endoscopy which is the usual process for diagnosing these conditions. Therefore, patients on the waiting list for endoscopy that meet specific criteria will be offered the Capsule Sponge test instead of endoscopy.

A Capsule Sponge is a small capsule on a string. The capsule is a similar size to a vitamin tablet and is made from vegetarian gelatin. The capsule contains a sponge which is designed to collect a sample of cells from your oesophagus (gullet). This will then be tested to find out if there are any cells which are unexpected or abnormal.

Problems with heartburn and acid reflux are very common but occasionally this can lead to changes in the normal cells that line your oesophagus (gullet).

Very rarely these cells can develop into pre-cancerous or cancerous cells and may lead to oesophageal cancer (cancer of the gullet). When changes to cells are found early it can make any treatment much simpler and the impact on a patient is much less significant.

A Capsule Sponge test can help your doctor investigate and manage your symptoms.

Before your test appointment

  • You should keep taking all your usual medications
  • If you take any blood thinning medication please read the alert for patients on Warfarin on page 7 of this leaflet. If you take Warfarin you will need to have an INR test 7 days before your Capsule Sponge test.
  • If you have diabetes please make sure your appointment is a late morning appointment (as you cannot eat or drink for 4 hours before your appointment)
  • If you have any questions about the test or find that you cannot keep your appointment, please contact the clinic using the contact details on your Capsule Sponge referral letter

On the day of your test

  • You should have nothing to eat or drink for 4 hours before your appointment
  • Take your medication as normal, but with only a little water. Please bring a list of your medications with you to your appointment
  • If you are on blood thinners you will have had separate instructions
  • If you have diabetes please have a light breakfast early in the morning (a minimum of 4 hours before your appointment) and take your usual medication

At the hospital or clinic

  • Please arrive on time for your appointment so that we can manage the number of patients in the clinic. Please do not arrive early for your appointment
  • Your appointment will last around 30 minutes
  • If you have any questions when you arrive, please ask your nurse when you are checking in

What happens during the test?

  1. You will be collected from the waiting room by one of the nursing team who will take you to the clinic area, your appointment will take up to half an hour.
  2. You will be asked some questions to check that you are ready for your test and make sure you are comfortable
  3. You will swallow the Capsule and string with some water. The end of the string is attached to a piece of card which the nurse will hold
    Swallowing the Capsule diagram
  4. It will take around 7½ minutes for the capsule to dissolve, releasing the sponge in your stomach
    Capsule dissolving in the stomach
  5. The nurse will pull up the sponge by the string. This will only take 1 or 2 seconds and should not be painful, but you may feel like the inside of your gullet is being brushed.
    A nurse wearing gloves holding the string
  6. The sponge collects cells as it passes through your gullet
    The sponge collecting cells in the gullet as it is removed
  7. After your test, experts will look at the sample to see if you have any signs of changes to the cells in the oesophagus (gullet)
    A worker in a lab coat studying the cells under a microscope

You will be given the option to have a local anaesthetic spray into your throat which will numb the area before the sponge is removed, as some patients may find this step uncomfortable. If you choose to have a local anaesthetic spray, the nurse will first make sure you do not have any allergies, and that you are not taking any medication that would cause this to be a problem.

After your test

  • You can go home straight after you test is completed
  • If you have had a local anaesthetic spray, this causes a numbing in your throat which will soon go away. For safety reasons you will be advised not to eat or drink for 20-30 minutes after the test. After this you can eat and drink as normal
  • If you have a sore throat after the test, suck a throat lozenges or sweet and take simple painkillers like paracetamol if required
  • If your heartburn symptoms become worse, you should continue to take your heartburn medication as prescribed
  • It is very unlikely you will experience any other symptoms, however if you experience any severe pain or bleeding you should contact the clinic using the contact details on your referral letter. Outside normal opening times, please call 111 telling them that you have had a Capsule Sponge test

How will you get your results?

The results of your test will be given to you either by telephone or by letter. We expect this to take around 2-3 weeks following your procedure.

If your Capsule Sponge test shows your cells are normal, this indicates that there is no evidence of damage to the oesophagus, and you will continue with treatment, such as acid-suppressants for your symptoms.

If the Capsule Sponge tests identifies any abnormal cells, this indicates that there is some damage to the oesophagus which will require further investigation with an endoscopy.

Potential risks

  • The Capsule Sponge test has not been found to have any serious side effects
  • Most people do not have any problem swallowing the capsule but if you do have a problem, we will not continue with the test
  • You may have a mild sore throat which might last up to 48 hours after the test
  • There is an extremely small risk (less than 1/1000) that the string may become detached from the sponge or it may be difficult to remove the sponge. If this happens it is not painful or dangerous, but you will have an endoscopy to remove the sponge (the same procedure you were originally refer for)
  • There is a very small chance that you may experience bleeding and this may be more likely if you are on blood thinning medication. If this happens please call us using the contact details on your referral letter. Outside normal opening times, please call 111 telling them that you have had a Capsule Sponge test

Like all tests, the Capsule Sponge may not always find all abnormalities. On very rare occasions, a serious abnormality might not be identified. If you have any questions about this, please contact the clinic using the contact details on your referral letter.

Are there alternatives to Capsule Sponge Test?

Capsule Sponge test has been proven in clinical trials to be a simple, safe and effective way of diagnosing conditions related to the oesophagus (gullet) and is being used in your hospital for low risk patients as an alternative to endoscopy.

If you decide not to have a Capsule Sponge test then an endoscopy will be offered. There will be a longer waiting time for an endoscopy due to the Covid-19 pandemic.

If you would like to discuss an alternative, please speak to your doctor.

Asking for your consent

If you decide to go ahead with the Capsule Sponge test we will ask you to sign a consent form on the day. This confirms that you agree to have the test and that you understand what it involves. You should make sure you have read and understood all the information you have been given. Once you have decided to have the test, bring the consent form with you to your appointment where it can be completed and signed before your procedure.

How will my data be protected?

Any member of NHS staff who has access to your confidential information is bound by NHS England confidentiality regulations and the Data Protection Act 2018 (DPA2018).

You can find more about data protection and the way NHS England handles and stores personal data on the NHS website.

Alert for patients on blood thinning medicines

If you are taking any blood thinning medications that may affect your clotting, you should have received specific instructions on what to do regarding these medications during the telephone call where your appointment was booked. If you have not received this information or have any questions contact the clinic using the details on your Capsule Sponge referral letter.


You will need to have an INR test the week before your Capsule Sponge test.

Your INR has to be 3.5 or less when you have the test.

If your INR is within your target range then continue with your usual dose.

If your INR is not within your target range, please contact your anticoagulant clinic for advice as your dose may need to be adjusted.

If your INR result is above 3.5 contact your anticoagulant clinic or GP for advice.

Anti-Platelet Medication

Clopidogrel, aspirin, prasugrel, ticagrelor and other anti-platelet medication do not need to be stopped before your Capsule Sponge test.

Other anticoagulants

You should stop any other anticoagulants the day of your Capsule Sponge test. E.g. Rivaroxaban, Apixaban, Edoxaban, Dabigatran.

Restart your medication the day after your test. Continue with your usual dose.

Frequently Asked Questions

How will Covid-19 affect my appointment?

You will need to be tested for Covid-19 three days prior to their appointment. You should then isolate and use private transport to attend the appointment. Please see more detail at the beginning of this leaflet.

What should I wear to my appointment?

Wear your normal clothes, you will be provided with a disposable bib.

What if I forget my Consent form?

Don’t worry – the nurse will have extra forms.

Will the test hurt?

The test should not be painful, you may feel like the inside of your gullet is being lightly brushed.

If you require this information in other languages or formats, please contact the clinic using the contact details on your referral letter.