A string test involves swallowing a string to obtain a sample from the upper part of the small intestine. The sample is then tested to look for intestinal parasites.
Duodenal parasites test; Giardia - string test
How the Test is Performed
To have this test, you swallow a string with a weighted gelatin capsule on the end. The string is pulled out 4 hours later. Any
How to Prepare for the Test
You may be asked not to eat or drink anything for 12 hours before the test.
How the Test will Feel
You may find it hard to swallow the string. You may have an urge to vomit when the string is being removed.
Why the Test is Performed
The test is performed when your health care provider suspects that you have a parasite infection. Usually a stool sample is tested first. A string test is done if the stool sample is negative.
No blood, parasites, fungi, or abnormal cells is normal.
Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your test results.
What Abnormal Results Mean
Abnormal results may be a sign parasite infection such as
Treatment with certain drugs can affect the test results.
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Hill DR, Nash TE. Giardia lamblia. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 281.
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Review Date: 04/11/2018
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