Following a CT Colonography 

You have had a procedure called a CT colonography today. This is a test that uses CT scans to check the large bowel (colon). 

Please keep this leaflet to hand so you can refer to it over the next few days. If you have any further questions, please speak to a member of your healthcare team who will be pleased to advise you. 

After your procedure 

• As soon as you are comfortable enough to leave the department, you will be free to go home.

• If you had an injection of Buscopan, your eyes may be blurry after the procedure. This should last no longer than 45 minutes. Do not drive until your eyesight has returned to normal.

• You may feel bloated, have more wind than normal or have diarrhoea today. We advise you to stay within easy reach of a toilet.

• You may return to your normal diet. Try to drink plenty of fluids for the next few days.

• Some patients experience soreness around their back passage because of the preparation for the test. If this is the case, an appropriate cream may help. Please consult your local pharmacist.

• If you stopped taking iron tablets in preparation for this procedure, you should start to take them again. 

Your results 

Images that were taken of your bowel will be reviewed by a consultant radiologist. The results will then be discussed with you at your follow-up outpatient appointment. 

Possible side effects 

A CT colonography is a very safe procedure. You should not experience any issues. However, please be aware that you may experience some of the side effects below for 48 hours after the procedure. 

• You may feel bloated from the carbon dioxide gas. This feeling should ease within a few hours, as your body absorbs the gas, or you pass it from your bottom. Moving around and eating will usually help to ease any discomfort. 

•  A small perforation (hole in your bowel wall) is a possible, but rare, side effect of CT colonography (one in 3,000 cases). If you suffer from a severe pain or prolonged discomfort in your tummy, chills, fever or nausea and vomiting, you must telephone 111 or attend the emergency department of your local hospital. Perforations made in this way will usually heal without treatment. However, you may be prescribed antibiotics and required to stay overnight in hospital. 

• If you were given an injection of Buscopan used to relax your muscles, you may develop a very rare reaction of painful red eyes and loss of vision. This usually happens within the 24 hours after your procedure. If you develop these symptoms, you should seek immediate medical advice from the emergency department or the eye casualty department of your local hospital. 

• A delayed reaction to the intravenous contrast (x-ray dye) is a possible, but very rare, side effect. This may cause a rash to appear over the next few days or itching across your whole body. If this happens, phone 111 or speak to a pharmacist. 

• If you develop shortness of breath, or your throat or face start to swell, seek urgent medical help. 

If you do experience any of these side effects, please let the radiology department know so we can note this on your radiology information system record. 

Contact numbers

If you would like further medical advice, please contact the radiology department. You can also contact your GP or the NHS helpline, who will be able to help you with any medical problems. 

Radiology Department: 01305 255397 (Monday to Friday, 9am to 4.30pm) 

NHS helpline: 111 (available 24-hours a day, seven days a week) 

What are the risks and complications? 

If you have any concerns or issues about your treatment which have not been answered by the Radiology Department, please contact our Patient Advice Liaison Service (PALS) on 0800 7838058 or email patientexperience@dchft.nhs.uk

About this leaflet

Author: Ophelia Walters
Written: August 2024
Updated and approved: June 2025 
Review date: June 2028 
Edition: v1 

If you have feedback regarding the accuracy of the information contained in this leaflet, or if you would like a list of references used to develop this leaflet, please email patientinformation.leaflets@dchft.nhs.uk