Test Catalog

Test Id : LEU

Fecal Leukocytes, Feces

Useful For
Suggests clinical disorders or settings where the test may be helpful

Suggesting the presence of pathogens such as Salmonella, Shigella, and amebiasis

Method Name
A short description of the method used to perform the test


Includes trichrome stain.

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Fecal Leukocytes

Lists additional common names for a test, as an aid in searching

Leukocytes, Fecal

Specimen Type
Describes the specimen type validated for testing



Question ID Description Answers
Q00M0034 Specimen Source

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies: ECOFIX Stool Transport Vial (Kit) (T219)


Preferred: ECOFIX preservative

Acceptable: Polyvinyl alcohol (PVA) preservative

Specimen Volume: Representative portion of collection

Collection Instructions:

1. Collect a random fecal specimen.

2. Carefully follow instructions on container.


Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Fecal Ambient (preferred) 21 days PVA OR ECOFIX
Refrigerated 21 days PVA OR ECOFIX

Useful For
Suggests clinical disorders or settings where the test may be helpful

Suggesting the presence of pathogens such as Salmonella, Shigella, and amebiasis

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Leukocytes are not normally seen in feces in the absence of infection or other inflammatory processes. Fecal leukocytosis is a response to infection with microorganisms that invade tissue or produce toxins, which causes tissue damage.


Fecal leukocytes are commonly found in patients with shigellosis and salmonellosis and sometimes in amebiasis. Mononuclear cells are found in typhoid fever.


Ulcerative colitis may also be associated with fecal leukocytosis.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Interpretive report

Provides information to assist in interpretation of the test results

When fecal leukocytes are found they are reported in a semiquantitative manner: "few" indicates < or =2/oil immersion microscopic field (OIF); "moderate" indicates 3/OIF to 9/OIF; "many" indicates > or =10/OIF.


The greater the number of fecal leukocytes, the greater the likelihood that an invasive pathogen such as Salmonella or Shigella is present.


Few or no leukocytes and many erythrocytes suggests amebiasis.


Fecal leukocytes are rarely seen in diarrheas caused by other parasites or viruses.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Fecal leukocyte examinations cannot be performed on formalin-preserved specimens. Therefore, ECOFIX-preserved or polyvinyl alcohol-preserved feces must be sent to the laboratory.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

Pickering LK, DuPont HL, Olarte J, et al: Fecal leukocytes in enteric infections. Am J Clin Pathol 1977;68:562-565

Method Description
Describes how the test is performed and provides a method-specific reference

Feces preserved in ECOFIX preservative or polyvinyl alcohol are stained with trichrome. (Garcia LS: Diagnostic Medical Parasitology. Fifth edition. ASM Press Dec 28, 2007)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Saturday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 2 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

3 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
LEU Fecal Leukocytes 13655-6
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
LEU Fecal Leukocytes 13655-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports