D-Xylose Absorption Test
How It Feels
Drinking the D-xylose solution can make you feel sick to your stomach (nauseated).
The blood sample is taken from a vein
in your arm. An elastic band is wrapped around your upper arm. It may feel
tight. You may feel nothing at all from the needle, or you may feel a quick
sting or pinch.
There is no pain while collecting a
5-hour urine sample.
There is very little chance of a
problem from having a blood sample taken from a vein.
- You may get a small bruise at the site. You
can lower the risk of bruising by keeping pressure on the site for several
- In rare cases, the vein may become swollen after the blood
sample is taken. This problem is called phlebitis. A warm compress can be used
several times a day to treat this.
- Ongoing bleeding can be a
problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and
other blood-thinning medicines can make bleeding more likely. If you have
bleeding or clotting problems, or if you take blood-thinning medicine, tell
your doctor before your blood sample is taken.
This test can cause
dehydration. Make sure that you drink enough fluids to
replace lost liquids after you have completed the test.
Drinking the D-xylose preparation may cause vomiting and diarrhea. Tell your doctor if you have problems after drinking the
The D-xylose test measures the level of
D-xylose, a type of sugar, in a blood or urine sample.
levels of D-xylose are highest about 2 hours after drinking the D-xylose
solution. Almost all of the D-xylose is eliminated from the body in the urine
within 5 hours. If the
intestines can't absorb the D-xylose properly, the
amount of D-xylose in the blood and urine will be very low.
conditions can change D-xylose levels. Your doctor will discuss any significant
abnormal results with you in relation to your symptoms and past health.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
D-xylose in blood1
Infants (5-gram dose):
More than 15
milligrams per deciliter (mg/dL) or more than 1.0
millimole per liter (mmol/L)
Children (5-gram dose):
More than 20 mg/dL or more than 1.3
Adults (5-gram dose):
More than 20 mg/dL in 2 hours or more
than 1.3 mmol/L
Adults (25-gram dose):
More than 25 mg/dL in 2 hours or more
than 1.6 mmol/L