How does a colon transit scan work?

By tracking the movement of a radiotracer through your bowel over a 5 day period.

Why am I having a colon transit scan?

Evaluation and clinical diagnosis of constipation.

What happens when I have a Colon Transit scan?

A small amount of radioactive tracer is mixed into a cup of milk. You then drink the milk. A scan is taken 6 hours after you have had the milk. Scans are then taken every day thereafter for the rest of the week.

Are there any side effects?

None. You will receive a small amount of radiation from the radiotracer that is well within safety limits.

How long will this test take?

The scans take 10 minutes each day. On the first day you will need to return to the department 6 hours after your initial visit. You will be taken into a scanning room and you will lie on a bed with the gamma camera underneath the table.

What are the preparations that I need to take?
  • No laxatives for 48 hours before and during the 5 day study.
  • Your first appointment will be on a Monday morning.
Are there any restrictions during or after the scan?


If you are breast feeding, pregnant or think that you might be pregnant, please tell the technologist BEFORE the first injection.

What should I do following the test?

We ask that you:

  1. Keep yourself well hydrated for the next 24 hours. A substantial amount of the Tc99m injection will pass out through your urine.
  2. Keep your distance from pregnant woman or children.
  3. If you are seeing your doctor or any other health professional immediately after your scan please notify them that you are still a source of radiation.
  4. We ask that you do not schedule any other appointments for yourself for the rest of the day.



9716 3600


 8042 3000


9911 6800

Five Dock

8705 8300


9598 0100


8228 9000

North Strathfield

8282 8100

North Sydney (Mater Imaging)

9955 4466
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