Smear of duodenal fluid aspirate

Definition

Smear of duodenal fluid aspirate is an exam of fluid from the duodenum to check for signs of an infection (such as giardia or strongyloides). Rarely, this test is also done in a newborn to check for biliary atresia.

Alternative Names

Duodenal aspirated fluid smear

How the Test is Performed

A sample is taken during an upper endoscopy (esophagogastroduodenoscopy, also called an EGD).

How to Prepare for the Test

Do not eat or drink anything for 12 hours before the test.

How the Test will Feel

You will be given medicines to help you relax and sometimes sleep. Occasionally, you may feel a gag sensation, but the medicines used make this test very comfortable. If you get anesthesia, you cannot drive for the rest of the day and will need a ride home from the procedure location.

Why the Test is Performed

The test is done to look for infection of the small bowel. However, it is not often needed. In most cases, this test is only done when a diagnosis cannot be made with other tests.

Normal Results

There should be no disease-causing organisms in the duodenum. Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

The results may show the presence of giardia protozoa, the intestinal parasite strongyloides, or another infectious organism.

Risks

The risks of this test include:

• Bleeding
• Perforation of (poking a hole in) the gastrointestinal tract by the scope
• Infection

Some people may not be able to have this test because of other medical conditions.

Considerations

Other tests that are less invasive can often find the source of the infection.

References

Diemert DJ. Nematode infections. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 327.

Dobbs KR, Dent AE. Strongyloidiasis (Strongyloides stercoralis). In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 341.

Mathison BA, Pritt BS. Parasitology. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. St Louis, MO: Elsevier; 2023:chap 88.