String testDefinition: This test involves swallowing a string to obtain a sample, which is then tested to detect the presence of intestinal parasites. The string test is rarely performed in the U.S.
Alternative Names: Duodenal parasites test
How the test is performed: You swallow a string with a weighted gelatin capsule on the end and then it is pulled back out after 4 hours. Any bile, blood, or mucus attached to the string is examined under the microscope for cell types and segments of parasites or eggs.
How to prepare for the test: Food and fluid may be restricted for 12 hours before the test.
How the test will feel: You may find it difficult to swallow the string, and you may feel an urge to vomit when the string is pulled up.
Why the test is performed: The test is performed when there is a suspicion of parasitic infestation but parasites are not detected by stool examination.
Normal Values: No presence of blood, parasites, fungus, abnormal cells, or bile is normal.
What abnormal results mean: Abnormal results may indicate the presence of giardia or another parasitic infestation.
Special considerations: Previous drug therapy can affect the test results.
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