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D-Xylose Absorption Test

Test Overview

The D-xylose absorption test measures the level of D-xylose, a type of sugar, in a blood or urine sample. This test is done to help diagnose problems that prevent the small intestine from absorbing nutrients in food.

D-xylose is normally easily absorbed by the intestines. When problems with absorption occur, D-xylose is not absorbed by the intestines, and its level in blood and urine is low.

Why It Is Done

A test for D-xylose is done to:

  • Check to see if malabsorption syndrome is causing symptoms, such as chronic diarrhea, weight loss, and weakness. A person with malabsorption syndrome is unable to absorb nutrients, vitamins, and minerals from the intestinal tract into the bloodstream.
  • Find the cause of a child's failure to gain weight, especially when the child seems to be eating enough food.

How To Prepare

For 24 hours before a D-xylose test, do not eat foods high in pentose, a sugar similar to D-xylose. These foods include fruits, jams, jellies, and pastries.

Medicines such as aspirin and indomethacin can interfere with the results of a D-xylose test. For this reason, your doctor may instruct you to temporarily stop these medicines before the test.

Do not eat or drink anything except water for 8 to 12 hours before having this test. Follow the doctor's instructions about how long your child needs to avoid eating and drinking before the test.

A D-xylose test can take a long time. It might be a good idea to bring something you can do quietly while you wait, such as a book to read.

How It Is Done

The amount of D-xylose in urine and blood samples is measured before and after you drink a D-xylose solution. To begin the test, a sample of your urine and a sample of your blood may be collected.

Next you will drink a D-xylose solution. For adults, a blood sample is usually taken 2 hours after they drink the solution. For children, a blood sample may be taken 1 hour after they drink the solution. More blood samples may be drawn during the test.

You will need to collect all of the urine you produce for 5 hours after you drink the sugar solution. You will be told to rest or lie down during the test. And you won't be able to eat until the test is completed.

How It Feels

Blood test

When a blood sample is taken, you may feel nothing at all from the needle. Or you might feel a quick sting or pinch.

Urine test

There is no pain while collecting a 5-hour urine sample.

Risks

There is very little chance of having a problem from this test. When a blood sample is taken, a small bruise may form at the site.

Results

Normal

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

Low values

Low values may be caused by:

  • A disease that interferes with the intestine's ability to absorb nutrients (malabsorption syndrome), such as celiac disease, Crohn's disease, or Whipple's disease.
  • Inflammation of the lining of the intestine.
  • Short bowel syndrome.
  • An infection with a parasite, such as giardiasis or hookworm.
  • An infection that causes vomiting (such as food poisoning or the flu).

Credits

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff
Clinical Review Board
All Ignite Healthwise, LLC education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Current as of: April 30, 2024

Author: Ignite Healthwise, LLC Staff

Clinical Review Board
All Ignite Healthwise, LLC education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

Dear patient

I am excited to announce that I will be relocating my practice to Houston Methodist DeBakey Cardiology Associates. Starting November 4, 2024, my new address will be:

5115 Fannin, Suite 801
Houston, TX 77004

Please note that my phone number and fax number will also change to the following:
24-Hour Telephone: 713-441-1100
Fax: 713-790-2643
Clinical Support Telephone (M-F, 8-5): 713-441-3515

I am excited about caring for you in my new office and hope you will make the transition with me. I will also continue to refill your medications as I have in the past. To assist, please provide your pharmacy with my new contact information.

Please consider checking your prescription refills to verify that you have enough medication on hand to last you until your next visit. Please note that your medical records will remain at my former office until you authorize their transfer. If you choose for me to continue providing your medical care, please complete and sign the enclosed “Authorization for Release of Medical Records” form and fax it to 713-790-2643. Once we receive your authorization, we will be happy to process the request for you.

Thank you for entrusting me with your medical care. My new team and I are dedicated to making this transition as seamless as possible. For help scheduling an appointment and transitioning your care, please call my new office number above.

I look forward to continuing your care at my new location.

Sincerely,
Gopi A. Shah, MD

Dear patient

Dr. Albert Raizner, Dr. Michael Raizner, and Dr. Mohamed El-Beheary are excited to announce that our practice, Interventional Cardiology Associates, will merge with Houston Cardiovascular Associates on November 1, 2024.

Our new offices are similarly located in Houston, near the Texas Medical Center and in Sugar Land. Our in-hospital care will continue at Houston Methodist Hospital in the Texas Medical Center and Houston Methodist Sugar Land Hospital. Importantly, our new offices expand our services with state-of-the-art equipment and amenities. Our core values will always be, as they began over 40 years ago when Dr. Albert Raizner founded ICA:

Integrity – Compassion – Accountability

Our new address and contact information are:

Your medical records are confidential and remain available at our new locations. We consider it a privilege to serve as your cardiologists and look forward to your continuing with us. However, should you desire to transfer to another physician, you may request a copy of your records by contacting us at our new addresses and phone numbers listed above.

We thank you for your trust and loyalty. As always, we will continue to be here to take care of you. Please do not hesitate to contact us if you have any questions or concerns.

Sincerely,

Dr. Albert Raizner,
Dr. Michael Raizner,
Dr. Mohamed El-Beheary