Smear of duodenal fluid aspirate is an examination of fluid taken from the duodenum, for a possible infection. Usually the health care practitioner is looking for either giardia or strongyloides, which are parasites.

The specimen is obtained by esophagogastroduodenoscopy ( EGD). The doctor passes a flexible scope through the mouth and stomach to the duodenum in order to view the organs and obtain specimens. If the tube is passed without EGD, its position in the body can be confirmed by the pH (acid-base balance) of the fluid obtained, or by an x-ray.

Fluid is suctioned up from the duodenum when the tube or the scope is in proper position. The fluid is placed on a microscope slide and stained for examination.

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

You may have a gagging sensation as the tube is passed, but the procedure is usually not painful.

The test is done to diagnose infection of the small bowel, but it is only rarely necessary. In most cases, this test is only done when a diagnosis could not be made with a stool examination and a duodenal string test.

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

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

The risks include bleeding, perforation of (poking a hole in) the gastrointestinal tract by the scope, and infection. Certain pre-existing conditions may prohibit use of this test.

Other, less invasive, tests can often detect the presence of giardia and other infections.

Kazura JW. Nematode infections. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 378.

Sears CL. Giardiasis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 372.