Preparing for CT Colonography

​What is CT Colonography?

A CT Colonography (CTC) uses X-rays to capture images of the large intestine (or colon), to detect cancer and smaller growths (polyps). It is an alternative examination to Optical Colonoscopy (OC). Studies have shown that CTC has similar rates of detection of cancer and certain types of polyps when compared to OC, though it may not be able to pick up very small or flat polyps. 

How do I prepare for the CT Colonography Procedure?

You are to come to the Radiology Department at least 2 weeks before your scan, to perform a screening with our radiographer and to collect the medication for bowel preparation.

Preparation for scan will begin 2 days before your scan appointment date:

• 2 Days before the scan, you should be on Low Residue Diet:
• • Lean meat
  • Porridge
  • White Bread
  • Steamed Fish
  • Boiled Potatoes
  • NO vegetable and fruits
  • NO dairy products
  • NO Oats/whole meal
• 1 Day before the scan:
• • NO solid food, only Clear Liquids allowed
  • NO Dairy Products
  • You should also consume the colonic lavage solution and bisacodyl tables as directed by the Radiographer upon collection.
• Day of the scan
  
• • DO NOT take any food before your CT scan
  • Only plain water is allowed
    
• An intravenous cannula will be inserted on your arm before the examination commences, if necessary. 
  
• You may be asked to do a blood test for Creatinine Serum on the day of the scan, if required
• • Waiting time for results may be as long as 2 hours
    
• If you are on Sodium Glucose Co-transporter 2 (SGLT-2) Inhibitors [Dapagliflozin (Forxiga/Xigduo XR), Empagliflozin (Jardiance/Jardiance Duo/Glyxambi), Canagliflozin (Invokana)], please discontinue 2 days before the procedure.
• If you are on anti-diabetic medication, do not take it the morning of your exam.
• If you are on any other medications, continue your medication as per normal.
• Please contact DDR Call Centre (6321-4225) if you have an allergy to CT contrast media e.g., Iohexol, Iopamidol, Iopromide.