Small bowel tissue smear is a laboratory test that checks for disease-causing substances in a sample of tissue from the small intestine.

A sample of tissue from the small intestine is removed during a procedure called esophagogastroduodenoscopy (EGD). For more information on this procedure, see EGD.

The sample is sent to a laboratory, where it is sliced, stained, and placed on a microscope slide for examination.

For information on how to prepare for the removal of tissue from your small intestine, see EGD.

The laboratory smear does not involve the patient, so there is no pain. For information on how it will feel to have a sample of intestinal tissue removed, see EGD.

Your doctor may order this test if you have signs or symptoms of an infection of the small intestine. In most cases, this test is only done when stool examinations and duodenal string test have been unable to confirm a diagnosis.

A normal result means no disease-related substances or changes were found in the sample when examined under the microscope.

However, the small intestine normally contains certain healthy bacteria and yeast. Their presence is not a sign of disease.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

An abnormal result means that certain microorganisms, such as the parasites Giardia and Entamoeba, were seen in the tissue sample.

A laboratory smear poses no risks to the patient. For risks related to obtaining a sample of intestinal tissue, see EGD.

Examination of tissue by a pathologist can help in the diagnosis of certain intestinal infections.