Patient Information – Bladder and Rectum preparation for Radiotherapy to the Pelvis

For your radiotherapy treatment, you would need to have a comfortably full bladder and empty rectum.

Why do I need to have a full bladder and an empty rectum for my treatment?

The picture on the left depicts an ideal treatment. The empty rectum is out of the treatment area and the full bladder pushes the intestines away from the treatment area. The picture on the right has a full rectum and empty bladder. This causes part of the rectum and intestines to be treated.

How do I achieve a comfortably full bladder?

Please ensure that you are well-hydrated by drinking 6-8 glasses of water daily. To ensure consistency, please follow these steps for your CT Simulation and daily treatment.

  1. 30 minutes before your CT Simulation procedure or treatment, empty your bladder,
  2. Then drink 2 styrofoam cups of water (approximately 400ml)
  3. Wait for approximately 30-60 minutes before the scan or treatment
  4. Your therapist would advise you to drink more water if your bladder is not full enough, or to relieve yourself if your bladder is too full.

How do I achieve an empty rectum?

Try to have a bowel movement in the morning of your CT Simulation and subsequently for your daily treatments. If you have irregular bowel movements, the doctor would be able to prescribe some medication to improve this.