Colonic Transit Study

The Colonic Transit Study uses a small amount of radioactive tracer (radiopharmaceutical) and a gamma camera to examine the function of the colon. This is an extended study taking up to seven consecutive morning appointments to complete. Its main use is in diagnosing disorders of bowel motility (ability to pass solid waste spontaneously).

  • Before your procedure

    What to bring

    • Your referral form
    • Any relevant previous imaging
    • Your Medicare card and any concession cards


    • A referral from your doctor or medical specialist, and an appointment is required for this examination.
    • You must have nothing to eat or drink for four hours prior to your appointment, apart from small amounts of water.
    • You must stop taking all forms of laxative at least 48 hours before your appointment time. Please ensure that you are available for an appointment each morning for a whole week, and also on the first Monday afternoon, and the following Monday morning.
    • If you are pregnant, breastfeeding, or caring for a small child on the appointment day, please notify us in advance for to receive special instructions.
  • During your procedure

    On your first visit to Apex Radiology a technologist will explain the procedure to you and ask you to drink some water containing a tasteless gallium tracer. You will then be free to depart for around six hours.

    On your return you will be asked you to remove any jewellery, watches etc, and then change into an examination gown. You will then be asked to lie on an examination table. A gamma camera will then be used to take a series of images over a ten minute period. During the scanning you may breathe normally, but must try not to move.

    The imaging process continues each morning at least until Thursday and usually Friday as well, and may need to be repeated on the following Monday, depending on the transit speed of your bowel. Each visit lasts for around 20 minutes.

    During the test, you should maintain your normal activities and eating habits, but take no laxatives at all. We will also ask you to note and report the time and date of all bowel motions during the examination period.

    The gamma camera is a large square radiation detector which sits close to the area being examined. You will experience no unusual sensations or discomfort from the scan.

  • Risks and side effects

    Nuclear medicine examinations are considered very safe with almost no reported adverse reactions attributable to the radiopharmaceuticals used in these examinations. Nuclear Medicine studies require very small doses of gamma radiation and are only performed where the benefits of the examination are deemed to outweigh any potential risks. At Apex Radiology you can be assured that using the latest technology and with staff trained in radiation reduction techniques, radiation doses are kept as low as reasonably possible.

    If you are worried or concerned about having a Nuclear Medicine study you should discuss this with your referring doctor or medical specialist before coming for your examination. If you think you may be pregnant, please inform our Nuclear Medicine team before your examination.

    For further information regarding radiation safety please visit:

  • Who will perform and report my examination?

    At Apex Radiology your stress test procedure will be carried out by a Nuclear Medicine Technologist who has a degree in Medical Radiation Science and is accredited by the Australian Health Practitioner Registration Agency (AHPRA). Your images will be reviewed along with your relevant medical history, and any other imaging, and be reported by our Nuclear Medicine credentialed radiologist or Nuclear Medicine physician (a medical doctor specialising in the interpretation of Nuclear Medicine studies).

  • After your procedure

    The radioactive tracer will decay over time and the body will eliminate any residue through the kidneys and bowel and you are free to resume normal activities. If you are caring for a small child, or breastfeeding, we may ask you to take some minor precautions.

  • How do I receive my results?

    If your results are needed urgently, or you have an appointment straight after your scan with your referring doctor or health care provider, Apex Radiology will arrange to have your results available immediately. Otherwise your referring doctor or health care provider will receive your report within 72 hours of your examination.

    Please ensure that you make a follow up appointment with your referring doctor or health care provider to discuss your results.

Make an appointment online or call our dedicated bookings line