Computed Tomography (CT) Colonography Gastrografin (morning) Appointment

Your doctor has advised you have a Computed Tomography (CT) colonography to help find the cause of your symptoms or as part of a routine screening programme to detect (find) disease or abnormalities (unusual areas) at an early stage in people with no symptoms.

This leaflet tells you about CT colonography. It will also help you to understand what will happen during and after your examination.

What is a CT Colonogrpahy?

A CT colonography is an X-ray examination, also known as a virtual colonoscopy. It is a type of body scan, which looks at the large intestine (bowel or colon). This can be carried out instead of a colonoscopy or barium enema.

Who will perform the test?

A specialist Radiographer (someone trained to take the scans) will carry out the examination and a Radiologist (a Doctor who specialises in X-rays, ultrasound and other similar types of examinations and reports on the findings) may be present.

What if I have a significant medical history?

If you have had previous bowel surgery or had a significant medical event in the last 6 weeks then please contact the CT appointments on 01429 522938. This will need further discussion with the radiologist and your consultant. If necessary, your investigation may need to be delayed by a few weeks based on your condition.

For female patients

If there is any chance of being pregnant please notify the department. If you take oral contraceptives and then have an episode of diarrhoea, this may reduce their effectiveness of the oral contraceptive. Continue taking oral contraceptives but use other precautions for the remainder of your cycle.

What are the risks and possible complications?

• Radiation: CT scans involve the use of radiation. Radiation risks from X-rays are small with the dosages used in this examination. The benefits of this examination outweigh any small radiation risk.

• Discomfort: You may feel some discomfort during the procedure; we try to keep this to a minimum. You can ask for the procedure to stop at any point if you wish.

• Bloating: You may feel bloated for a few hours afterwards. 

• Perforation (hole): One patient in every 3000 can suffer a perforation in the wall of the bowel¹. If this happens, treatment may be needed.

What will I need to do to prepare for my procedure?

It is very important that your bowel is empty and clean so that all areas of your bowel can be seen.

You must follow the instructions given in this leaflet.

Please read the back of the bottle and contact the specialist radiographers in the X-ray Department for further advice if you answer yes to any of the following questions (see contact numbers).

• Are you allergic to any of the ingredients listed on the bottle?

• Are you pregnant or breastfeeding?

• Do you suffer from any kidney disease?

3 days before your appointment

Stop any iron tablets you may be taking.

Stop any drugs that may cause you to be constipated, for example, Lomotil, Loperamide or Codeine phosphate.

Stop taking fybogel, senna or any other fibre products.

The day before your appointment

You will be asked to drink a liquid called Gastrografin the day before your scan. 

Gastrografin liquid is a commonly used preparation in radiology. It contains iodine. The liquid will have a laxative effect for most patients and causes diarrhoea. Do not worry if you find this is not the case for you. If you have any worries or concerns, please contact the X-ray Department for advice (see contact numbers).

If you have had any allergic reactions in the past to iodine products, including dye used in CT scans, please contact the department to discuss this. We may need to give you a different preparation.

You must also follow a low residue/low fibre diet. This includes white bread, rice, pasta, eggs, cheese and meat. Vegan alternatives such are also acceptable. For example tofu, quorn, soya products, etc.

The table below shows a suggested menu for the day. You can vary from this list, as long as the food consumed is low in fibre. However, please ensure the gastrografin liquid are consumed at the times specified.

The day before the scan

Breakfast

9am: drink half a bottle of gastrografin (50mls)
Eat and drink:
Choose one of the following:
2 slices of white bread /toast or Croissants with Butter/Marmalade/Jam
1 boiled/poached egg and a slice of toast
50g cottage cheese and 1 slice of toast
Tea and Coffee, fizzy drinks or fruit squash

Lunchtime

Eat and drink:
Choose one of the following:
75g meat/ fish/ tofu/ quorn
2 boiled or poached eggs
2 slices of white bread
2 egg sized potatoes – no skin
2 table spoons plain white pasta/ rice
Clear soups (e.g. strained chicken noodle soup)
Jelly, ice cream, custard

Drinks:

Complan drinks,
Bovril or Oxo
Water, clear juices, Lucozade, fizzy drinks
Coffee and tea

Tea time

6pm: drink other half bottle of gastrografin (50mls)
You can have a light supper of white toast only, together with a drink.
 
No solid food after this until after your appointment.

On the day of the scan

Do not have any solid food.
However drink plenty of clear liquids such as:
Clear soups (e.g. strained chicken noodle soup) Ensure drinks, Bovril and Oxo drinks, water, clear juices, Lucozade, fizzy drinks, coffee and tea

Information for Diabetic Patients

• Ideally, you will be given an early morning appointment.

• If you take insulin, please phone your diabetic liaison nurse (hospital or GP) for advice.

• Bring something to eat with you for after the test.

• If you are on a combination of long acting and short acting insulin injections, please contact us. We will need to ensure you have an early appointment.

• Insulin pumps will need to be removed before entering the scan room.

As you are at a risk of having a hypoglycaemic episode or ‘hypo’ (low blood sugar), it is important you test your blood sugar regularly.  As the preparation section states, you are allowed to drink fluids such as Lucozade, fizzy drinks and fruit juice (no bits) at any time.

Symptoms of a ‘hypo’ are sweating, shakiness, blurred vision, dizziness and confusion.

The day before the CT (Diabetic Patients)

• Take your usual insulin/diabetic tablets with your breakfast.

• Follow dietary instructions all day.

• When you are having fluids only: Reduce insulin doses by half and continue diabetic tablets as normal.

• Check your blood sugar regularly.

• If your blood sugar is below 5, drink sugary drinks to avoid having a ‘hypo’.

The day of the CT (Diabetic Patients)

• Continue to have sugary fluids up until your scan.

• Before you are due to have your scan, test your blood sugar, if possible.

• Bring your insulin/tablets with you and a light meal/sandwich with you to have after the test.

• Do not take any more insulin/tablets until after the scan.

In the rare case that you have an afternoon appointment, you should take your usual dose of insulin in the morning only. Do not take diabetic tablets.

What will happen when I arrive for my appointment?

You will be sent a letter asking you to attend the CT Department, which is in the main X-ray Department.

Before your examination, you will be taken to a private area. You will be given a hospital gown to put on and you will be asked to remove all of your clothing below the waist.

What will happen during my examination?

The Radiographer will discuss the procedure with you and complete a health questionnaire. If you have any further questions or concerns, please discuss with radiographer at this stage. You will then be asked to sign a consent form.

A cannula will be inserted in your vein to give a medication called buscopan – this medication will relax your bowel and make the procedure more comfortable.

You will be asked to lie down on the CT table on your left side, with your knees slightly bent.

A soft tube will then be gently inserted into your rectum (back passage). Carbon dioxide will be passed through the tube to inflate your bowel so that your Radiologist can see all parts of your bowel wall. This is done using an electronic pump so that the pressure inside your bowel is safely controlled. This can cause ‘windy’ discomfort for a short time.

Once the bowel is fully inflated, a CT scan is carried out. The examination can take up to 20 minutes to complete. Any symptoms will quickly pass when the tube is removed and you go to the toilet.

Usually, two scans are taken in different positions, the first with you lying on your back and the other on your tummy or side. You will need to keep still during this time. Sometimes a third scan may be needed if the radiologist needs more information.

Sometimes, an injection of contrast medium dye may be needed. This injection usually causes nothing more than a warm sensation passing through your body.

Will it be painful?

The procedure can sometimes be uncomfortable due to gas within your bowel. The buscopan medication will relax your bowel and help to make this procedure more comfortable.

Buscopan can make your mouth dry and sometimes cause blurred vision. This effect usually lasts 15 to 20 minutes. 

You can ask for the procedure to stop at any point if you wish.

What will happen after my examination?

You will be asked to stay in the department for 20 to 30mins after your procedure. If you feel well after this, you can go home. You will be able to eat and drink as normal. Take your medications as usual after the procedure.

How will I get my results?

You will not be told any results of the test on the day. If your GP requested the scan, the results will be sent to them. If a hospital Consultant has sent you for the scan, you will be invited to attend a follow-up appointment to discuss the results.

Contact

University Hospital of North Tees and Hartlepool Foundation Trust

X-Ray Department
Monday to Friday 9:00am to 5:00pm
Telephone: 01642 624842

Diabetes Specialist Nurse
Monday to Friday 9:00am to 5:00pm
University Hospital of North Tees: 01642 624519
University Hospital of Hartlepool: 01429 522594

Further information

1. The patient.co.uk website has more detailed information about CT colonography:www.patient.co.uk/health/CTColonography.htm
2. https://www.radiologyinfo.org/en/info.cfm?pg=ct_colo, accessed 12/04/17

References

1. https://www.gov.uk/government/publications/bowel-cancer-screening-imaging-use/bowel-cancer-screening-guidelines-for-ctc-imaging#patient-safety

Comments, concerns, compliments or complaints

We are continually trying to improve the services we provide. We want to know what we’re doing well or if there’s anything which we can improve, that’s why the Patient Experience Team (PET) is here to help. Our Team is here to try to resolve your concerns. The office is based at the University Hospital of North Tees if you wish to discuss concerns in person. Our contact details are:

Telephone: 01642 624719 Freephone: 0800 092 0084

Monday to Friday, 9.30am to 4.00pm

Email: [email protected]

Out of hours if you wish to speak to a senior member of Trust staff, please contact the hospital switchboard (number below).

Out of hours

Out of hours if you wish to speak to a senior member of Trust staff, please contact the hospital switchboard who will bleep the appropriate person.

Telephone: 01642 617617

Patient, Public and People with Lived Experience

We are looking for patients to share their experiences of healthcare and to join our Involvement Bank. Working with the patients, carers, families and the general population we support in making decisions about their care can lead to better health outcomes, increased patient satisfaction and a better overall experience. We want to listen and work with you in shaping the future of your healthcare services. To find out more about the Involvement Bank go to our website or contact us at:

Website: www.nth.nhs.uk/about/community/people-with-lived-experience

Email: [email protected]

Data Protection and Use of Patient Information

The Trust has developed Data Protection policies in accordance with Data Protection Legislation (UK General Data Protection Regulations and Data Protection Act 2018) and the Freedom of Information Act 2000. All of our staff respect these polices and confidentiality is adhered to at all times. If you require further information on how we process your information please see our Privacy Notice at:

Website: www.nth.nhs.uk/support/privacy/

Telephone: 01642 383551

E-mail: [email protected]

Leaflet feedback

This leaflet has been produced in partnership with patients and carers. All patient leaflets are regularly reviewed, and any suggestions you have as to how it may be improved are extremely valuable. Please write to the Clinical Governance team, North Tees and Hartlepool NHS Foundation Trust, University Hospital of North Tees, TS19 8PE or:

Email: [email protected]

Leaflet Reference: PIL1320
Date for review: 18.09.2027