Schilling test

• On day 1, urinate into the toilet upon arising in the morning.
• Collect all subsequent urine (in a special container) for the next 24-hours.
• On day 2, urinate into the container in the morning upon arising.
• Cap the container. Keep it in the refrigerator or a cool place during the collection period. Label the container with your name, the date, the time of completion, and return it as instructed.

Infant:
Thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on your infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Place a diaper over the infant (bag and all). The infant should be checked frequently and the bag changed after the infant has urinated into the bag. For active infants, this procedure may take a couple of attempts--lively infants can displace the bag, causing an inability to obtain the specimen. The urine is drained into the container for transport to the laboratory.

Deliver it to the laboratory or your health care provider as soon as possible upon completion.

How to Prepare:
Fast (except for water) for 8 hours before starting the test, then eat normally for the next 24-hours.

The health care provider may advise you to discontinue drugs that can affect the test (see "Special Considerations").

If the collection is being taken from an infant, a couple of extra collection bags may be necessary.

How it Feels:
The injection of vitamin B12 may sting.

Risks:

• local reaction to injection of vitamin
• nausea
• feeling lightheaded

Why this Test is Performed:
The Schilling test is performed to evaluate vitamin B12 absorption. Normally, ingested vitamin B12 combines with an intrinsic factor , which is produced by cells in the stomach, and is absorbed in the distal part of the ileum (middle part of the small intestines).

Normal Values:
Excretion of 8 to 40% of the radioactive vitamin B12 within 24-hours is normal.

Abnormal Results:
Pernicious anemia results when absorption of vitamin B12 is inadequate. This may be caused by a primary malabsorption problem; possibly caused by an inflammation in the intestines, a deficiency of vitamin B12 in the diet, or a deficiency of intrinsic factor . The most common cause of intrinsic factor deficiency is surgical resection of part of the stomach as treatment for peptic ulcer . Other causes include genetic deficiency and development of an antibody that reacts against the intrinsic factor. Patients who have pernicious anemia from lack of intrinsic factor will have abnormal results on the 1-stage Schilling test (that is, the first test with out intrinsic factor) and normal results when on 2-stage Schilling test (that is, the second test performed about 1 week after the first and after intrinsic factor is given). Patients with malabsorption from an intestinal source will have abnormal results from both the 1- and 2-stage Schilling tests.

Abnormal 1- and 2-stage Schilling tests may indicate:

• biliary disease
• celiac disease (sprue)
• hypothyroidism
• liver disease

Lower-than-normal amounts of vitamin B12 absorption may indicate:

• biliary disease, resulting in malabsorption (inadequate absorption of nutrients from the intestinal tract)
• intestinal malabsorption (for example, related to sprue or celiac disease )
• liver disease (causing malabsorption)
• pernicious anemia

Additional conditions under which the test may be performed:

• anemia of B12 deficiency
• blind loop syndrome
• megaloblastic anemia

Cost:
The estimated cost is $77.

Special Considerations:
Interfering factors:

• renal insufficiency (inadequate kidney function)
• hypothyroidism
• laxatives may decrease the rate of absorption