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Stool Test for Blood: About Your Child's Test

What is it?

This test checks for signs of blood in your child's stool. You or your doctor will place a small sample of stool on a chemically treated card, pad, or wipe. Then a chemical solution goes on top of the sample. If the card, pad, or wipe turns blue, there's blood in the stool sample.

Why is this test done?

In children, a stool test for blood is most often done to see if what looks like blood in the stool really is. Or it may be done to see if bleeding from the digestive tract might be causing anemia.

How can you prepare for the test?

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

  • Tell the doctors ALL the medicines or natural health products your child takes. Some of these may affect the test. Your doctor will tell you which medicines your child should take or stop before the test.
  • 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 has her menstrual period, have her use tampons or wait until her period is over.

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

What happens during the test?

You can check for blood in your child's stool at home. There are different types of home tests you can use. 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.

General instructions

For any home test, follow these guidelines:

  • Check the expiration date on the package. Don't use a test kit after its expiration date. The chemicals in the kit may not work properly after that date.
  • Store the test kit as instructed. Many kits need to be stored in a refrigerator or cool place.
  • Read all of the instructions for your child's test closely before you do the test. Be aware of any special things your child needs to do before the test. This may include not eating certain foods.
  • Follow the instructions exactly. Do all the steps in order. Don't skip any of them.
  • If a step in the test needs to be timed, use a watch. Don't guess at the timing.
  • If you are colour-blind or have trouble seeing colours, have someone else read the test results for you. Most test results are colour changes on a test strip.
  • Write down the results of your child's test so you can discuss them with your doctor.

Stool guaiac cards

These instructions are for one of the most common tests used to find blood in the stool.

  • Complete the information on the front of each card.
  • During a bowel movement, collect a small amount of your child's stool on one end of an applicator. You might try catching the stool on some plastic wrap draped loosely over the toilet bowl and held in place by the toilet seat. If you use a container to collect the stool, first clean and rinse it well. This will get rid of any substance that may affect the test results. If your child still wears diapers, you can collect a sample from the diaper.
  • Apply a thin smear of stool inside box A.
  • Reuse the same applicator to get a second sample from a different part of the stool. Apply a thin smear inside box B.
  • Close the cover of the slide.
  • If you were told to complete more than one card, finish the remaining two cards in the same way for two other bowel movements.
  • Return all the samples right after you collect the last sample.

Other test kits

Some kits tell you to use a special cloth to wipe with after your child has a bowel movement. After wiping with the cloth, you put the developer solution on it to check for a colour 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 colour if the stool has blood in it.

Follow-up care is a key part of your child's treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse call line if your child is having problems. Ask your doctor when you can expect to have your child's test results.

Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.