Colonic Marker Study (Sitz Marker Study, Sitzmarks® Colonic Transit Study)

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Many children have problems with bowel movements. This test can provide useful information on how well stool moves through the colon.

Colonic Transit Time

Colonic transit (passage) time is the amount of time it takes for the food we eat to enter and leave the colon and pass out of the body. How often your child has a bowel movement relates to colonic transit time.

How to Prepare for the Test

You may be asked to cleanse your child’s bowel before the test. If you need to do this, you will get specific instructions. Two days before starting the test, you may need to stop giving your child any laxatives, stool softeners, enemas or suppositories (such as Miralax®, Dulcolax®, Bisacodyl, Ex-Lax®, and Senokot®). These may affect bowel function.Sitzmarks® Capsules

Your child should stop taking the following medicines:



A Sitzmarker® is a gelatin capsule that contains tiny rings (Picture 1). The rings show up on a special kind of X-ray. Your child can swallow the whole capsule with a glass of water. If your child is unable to swallow capsules, you may open the capsules and sprinkle the rings onto applesauce or pudding. Tell your child not to bite into the rings or chew them. Also, make sure that your child swallows all the rings.

Follow this schedule to prepare for the test:




Day 1


Give your child ONE Sitzmarks® capsule.

Day 2


Give your child ONE Sitzmarks® capsule.

Day 3


Give your child ONE Sitzmarks® capsule.

Day 4


Take your child to have a KUB X-ray done*.

Day 7


Take your child to have a second KUB X-ray done (Picture 2).

* Please note: If X-rays are taken outside of the Nationwide Children’s Hospital system, a CD of the images must be sent to your child’s GI doctor at: Nationwide Children’s Hospital GI Department 700 Children’s Dr. Columbus, Ohio 43205 Attention: Dr. _____________________. X-Ray of the Colon

After the Test

After the test is complete, if you were told to stop giving any medicines, your child may restart them as the doctor prescribed.

Risks and Possible Complications

If instructed, your child is not to take laxatives, stool softeners, enemas, or suppositories during this entire test. This is very important! If your child has discomfort from stopping these medicines, please call the child’s doctor.


When the test results are ready, our office will contact you. If you have any questions, be sure to ask your child’s doctor or nurse or call 614-722-3450.

Colonic Marker Study (PDF)

HH-III-108 06/06, Revised 10/19 | Copyright 2006, Nationwide Children’s Hospital