What tests should be done for a patient born in 1932, residing in a nursing home, who developed acute diarrhea (loose bowel movements) overnight without fever, blood, mucus, pain, or signs of being unwell?

From the Guidelines

For a nursing home patient born in 1932 who has developed loose bowel movements overnight without fever, blood, mucus, pain, or general unwellness, the most appropriate initial diagnostic test is stool testing for Clostridioides difficile (C. diff), as recommended by the 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea 1. This approach is based on the high prevalence of C. difficile infections in elderly nursing home residents, especially those who have recently received antibiotics.

• A complete blood count and basic metabolic panel should also be ordered to assess for signs of infection, inflammation, or electrolyte imbalances that may result from diarrhea.
• Stool culture and ova/parasite examination would help identify bacterial pathogens or parasitic infections.
• Testing for norovirus and rotavirus should be considered, as these are common causes of outbreaks in institutional settings, as noted in the 2017 guidelines 1.
• A medication review is essential to identify any recently introduced drugs that might cause diarrhea as a side effect.
• The 2015 systematic review on the diagnosis and treatment of Clostridium difficile in adults also supports the use of stool testing for toxigenic C. difficile or its toxins, or colonoscopic/histopathologic evidence of pseudomembranous colitis 1.
• It is crucial to ensure adequate hydration and monitor for signs of dehydration in this elderly patient, as older adults can decompensate quickly with fluid losses, highlighting the importance of prompt and appropriate management as discussed in the 2009 clinical practice guideline for the evaluation of fever and infection in older adult residents of long-term care facilities 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Diagnostic Approach

For a patient born in 1932 living in a nursing home who has developed loose bowel movements overnight with no fever, no blood, mucous, or pain, and is not unwell, the following diagnostic approach can be considered:

• The patient's symptoms suggest a possible Clostridioides difficile (C. difficile) infection, which is a common cause of healthcare-associated diarrhea 2, 3.
• Laboratory diagnosis of C. difficile infection is primarily based on clinical signs and symptoms, and is confirmed by laboratory testing 3.
• The diagnosis of C. difficile infection can be challenging, and episodes are often misdiagnosed due to lack of clinical suspicion or the use of inappropriate tests 3.

Recommended Tests

The following tests can be considered for diagnosing C. difficile infection:

• Stool culture for C. difficile, which is the most sensitive method for detection 4.
• Cell cytotoxin assay for detection of toxin B, which is the most specific method 4.
• Enzyme immunoassays for the detection of C. difficile toxins and the GDH house-keeping gene 5.
• Molecular assays, which have higher sensitivity and are becoming easier to incorporate into the test algorithm 5.

Interpretation of Test Results

• Test result interpretation can be challenging due to asymptomatic colonization of C. difficile in some patients, multiple guidelines, emerging resistant C. difficile ribotypes, and differences in disease prevalence 5.
• An accurate test result for diagnosis of C. difficile infection depends on selecting patients with high pre-test probability, collecting an acceptable stool specimen, and a thorough understanding of current test methods 5.
• The American College of Gastroenterology has published clinical guidelines for the prevention, diagnosis, and treatment of C. difficile infections, which can provide guidance on the management of adults with C. difficile infection 6.