Transit Study


This is an X-ray test which shows how long it takes (the transit time) for food to pass through your bowel. The purpose of the test is to try to find out what may be causing your symptoms (constipation).

We will ask you to swallow some special capsules – one a day for six days before the examination. Each capsule contains ten ‘radio-opaque’ markers which will show up on X-ray. These capsules and markers contain no medication and are inert so will pass through your tummy with no effect.

On the seventh day, after taking all the capsules, you will be asked to attend the X-ray department where we will take an X-ray picture of your abdomen.


Exposure to radiation: This is a low dose examination and the amount of radiation is kept to a minimum. This is equivalent to the amount of background radiation that you naturally receive over one month.

Your doctor has recommended this examination because he/she feels that the benefits are greater than the risks of not having the examination. Even so, this test cannot be guaranteed to detect all abnormalities in the bowel.


There are no alternatives to this procedure.


We will give you the six capsules which each contain ten radio-opaque markers which show up on X-ray. We will ask you to take one capsule a day for six days before the examination.

These capsules should be taken at the same time of the day over six days, preferably in the morning.

  • 1 capsule (labelled 1) on Day 1
  • 1 capsule (labelled 1) on Day 2
  • 1 capsule (labelled 2) on Day 3
  • 1 capsule (labelled 2) on Day 4
  • 1 capsule (labelled 3) on Day 5
  • 1 capsule (labelled 3) on Day 6

Please stop taking medications which affect your bowel movements (e.g. Fybogel, Lactulose, Dulcolax, Immodium, Movicol, Codeine, Iron tablets) for the duration of the test starting on the day you take your first tablet. You may take all your other medication as normal.

By stopping this bowel medication the doctor will be able to get a true picture of your bowel function. If you continue to take any of these medications the results of the test may be affected. If you are unable to stop your medication for six days, please call us.

You don’t need to follow any special diet before the examination so you can eat and drink normally.


The procedure usually lasts about 10 minutes but please be aware that occasionally there may be a delay if another patient needs to be seen very urgently.

You will be asked to change into a hospital gown to make sure that no metal coins/objects or bra straps are seen on the pictures. If you need to go to the toilet you should also do this before the test begins.

You will be asked to lie on your back on the X-ray table and the radiographer will take an X-ray of you abdomen. Once the radiographer has checked that the picture is adequate, the test is completed.


There are no side effects from these capsules and markers and they will be passed with your stool over the next few days.

X-ray image of ‘markers’ within the bowel.

X-ray image of ‘markers’ within the bowel.