Colonic Marker Study

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(Sitz Marker Study, Sitzmarks® Colonic Transit Study)

A child may have constipation if his or her stools are too hard, too infrequent, too painful, too large or if he cannot push it all out. Constipation is a symptom, not a disease. It can be caused by many different things.

This test helps us to find out the type of constipation your child has and how severe it is. This also gives us useful information about how well the colon is working.

Colonic Transit Time

Sitzmarks® Capsules

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 is related to colonic transit time.

How to Prepare for the Test

You may be asked to cleanse your child’s bowel before the test. If this is needed, you will be given specific instructions. Two days before starting the test your child should stop taking laxatives, enemas and suppositories (such as Dulcolax®, bisacodyl, Ex-Lax®, and Senokot®).

These may affect bowel function.

Your child should stop taking these medicines:



How the Test Is Done

A Sitzmarker® is a gelatin capsule that contains tiny rings (Picture 1). The rings show up on a special kind of X-ray. The capsule can be swallowed whole 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 yourchild swallows all the rings.

Follow this schedule to prepare for the test:

Day Date Instructions
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).
X-Ray of the Colon

*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, Attn: Dr. ______________________________.

After the Test

After the test, your child may take any laxatives or enemas your doctor has prescribed.

Risks and Possible Complications

NO laxatives are to be taken during this entire test. This is very important! If your child has discomfort from stopping the laxatives, please call your child’s doctor.


When the test results are ready, your doctor's 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 6/06, Revised 3/14  Copyright 2006, Nationwide Children’s Hospital