Bowel Transit Time
How To Prepare
Tell your doctor if you are or might
be pregnant before having this test.
You may need to change your diet for a few days before having this test. You may also need to stop taking medicines for a short time before having a bowel transit time test. Tell your doctor about all the prescription and nonprescription medicines you are taking.
Talk to your doctor about
any concerns you have regarding the need for the test, its risks, how it will
be done, or what the results will mean. To help you understand the importance
of this test, fill out the
medical test information form(What is a PDF document?).
How It Is Done
Your doctor will give you one or more gel capsules filled with markers that will show up on an X-ray. Follow your doctor's instructions about when to take the
capsules. You may take only one capsule. Or you may be told to take one at a certain time for 2 or 3 days in a row.
You will then have X-rays taken of your belly. These are usually done on day 5. The percentage of markers that show up on the X-ray tells your doctor if you have a normal bowel transit time.
How It Feels
Bowel transit time tests do not cause
You will not feel discomfort from the X-rays used for the test. The X-ray table may feel hard and the room may be cool. You may
find that the positions you need to hold are uncomfortable.
This test is not recommended if you are
pregnant because the radiation from the X-ray can harm your developing baby
A bowel transit time test measures how
long it takes for food to travel through the
digestive tract .
Bowel transit time depends on what types of food
you eat and how much you drink. Different people have different bowel transit
Bowel transit time
Fewer than 20% of the markers show up on an X-ray after 5 days (120 hours).
More than 20% of the markers show up on an X-ray after 5 days (120 hours).