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Introduction ⬇

Microscopic examination of stool for the presence of leukocytes (white blood cells) is performed as a preliminary procedure in determining the cause of diarrhea. Leukocytes are normally not present in stool and are a response to infection or inflammation.

The presence or absence of fecal leukocytes can provide diagnostic information before the isolation of a bacterial pathogen. Neutrophils (more than 3 neutrophils per high-power field) are seen in the stool in conditions that affect the intestinal wall (e.g., ulcerative colitis, invasive bacterial pathogen infection). Viruses and parasites usually do not cause neutrophils in the stool. The greater the number of leukocytes, the greater the likelihood that an invasive pathogen is present.

Normal Findings ⬆ ⬇

Negative for leukocytes

Procedure ⬆ ⬇

Collect a random stool specimen following the procedure for Collection and Transport of Random Specimens. Observe standard precautions. Mucus or a liquid stool specimen can be used. A fresh specimen is preferred, or it may be preserved in PVA.

Clinical Implications ⬆ ⬇

  1. Large amounts of leukocytes (primarily neutrophils) accompany the following conditions:

    1. Chronic ulcerative colitis

    2. Bacillary dysentery

    3. Localized abscesses

    4. Fistulas of the sigmoid rectum or anus

    5. Shigellosis

    6. Salmonellosis

    7. Yersinia infection

    8. Invasive E. coli diarrhea

    9. Campylobacter infection

  2. Primarily mononuclear leukocytes appear in typhoid. A few leukocytes are sometimes seen in amebiasis.

  3. Absence of leukocytes is associated with the following conditions:

    1. Cholera

    2. Nonspecific diarrhea (e.g., drug or food induced)

    3. Viral diarrhea

    4. Amebic colitis (many red blood cells)

    5. Noninvasive E. coli diarrhea

    6. Toxigenic bacteria (e.g., Staphylococcus, Clostridium)

    7. Parasites (e.g., Giardia, Entamoeba)

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain purpose of test, procedure for stool collection, and interfering factors.

  2. Advise the patient to avoid barium procedures and laxatives for 1 week before stool specimen collection.

  3. Do not start antibiotic therapy until after collection.

  4. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed. Monitor for diarrhea. Counsel the patient regarding abnormal findings; explain the need for follow-up tests (stool culture) and treatment (e.g., antibiotic drugs).

  2. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Interfering Factors ⬆

Testing for fecal leukocytes cannot be performed on formalin-preserved specimens.