The presence of fecal leukocytes indicates bowel mucosal inflammation.
Occurs in invasive bacterial enteritis Crohn’s disease and ulcerative colitis.
The sensitivity of the test is approximately 70% for diarrheal disease caused by Shigella, but lower for other bacterial pathogens.
The sensitivity of fecal leukocyte test for bacterial pathogens in children is only 65%.
The test should not be ordered on patients developing diarrhea after more than 3 days hospitalization, because the likelihood of bacterial enteritis is very low.
Fecal leukocyte counts are not reliable enough to be used when infectious diarrhea must be ruled out, such as the evaluation of an immunocompromised patient. Culturing the stool is more cost efficient in these circumstances.
Reference value is no WBC’s seen.
Specimen requirement is stool submitted as a smear on a glass slide, on a swab, or in a sterile, screw-capped container.