Stool Test for Blood: About Your Child's Test

What is it?

This test checks for blood in your child's stool. There may be such a small amount of blood that you can't see it. You or your doctor will place a small sample of stool on a special card and add a chemical. The card will change color if blood is in the sample.

Why is this test done?

In children, a stool test for blood may be done to see if what looks like blood in the stool really is blood. There are many causes for blood in the stool, and most aren't serious.

How do you prepare for the test?

If you're going to test for blood in your child's stool at home, your child may need to avoid certain medicines, supplements, and foods for 2 to 3 days before the test.

• Tell the doctor ALL the medicines, vitamins, supplements, and herbal remedies your child takes. Some may increase the risk of problems during the test. Your doctor will tell you if your child should stop taking any of them before the test and how soon to do it.
• Ask your doctor what foods your child should avoid. Some foods can cause the test to be positive for blood when blood is not in the stool.

If your child is having a menstrual period, have your child use tampons or wait until the period is over.

Don't test a stool sample that's been in contact with toilet bowl cleaning products that turn the water blue.

How is the test done?

You can check for blood in your child's stool at home. There are different types of home tests you can buy without a prescription. Make sure to follow the instructions that come with any test. For most tests, you will use stool samples from three different bowel movements over three different days. Or your doctor may just want you to test a sample that you think has blood in it.

For any home test, follow these guidelines:

• Check the expiration date on the package. Don't use a test kit after its expiration date.
• Store the test kit as instructed. Many kits have to be stored in a refrigerator or cool place.
• Follow the instructions exactly. Do all the steps in order, without skipping any of them. Be aware of any special things your child needs to do before the test. This may include not eating certain foods.
• Write down the results of your child's test so you can discuss them with the doctor.
• After your child finishes the test, follow the instructions that you were given for returning the test.

For a gFOBT test, you put a small sample of stool on a card that comes with the kit.

You may need to return the tube or card to your doctor or a lab. Some tests may show a result right away.

Some kits provide a special cloth to wipe with after your child has a bowel movement. After wiping your child with the cloth, you put the developer solution on it to check for a color change that means there is blood in the stool.

Other kits have a special test pad that you place in the toilet after a bowel movement. The pad will change color if your child's stool has blood in it.