From the Guidelines
For a 41-year-old female with chronic diarrhea and lower abdominal pain for one year without insurance, I recommend a cost-effective laboratory workup including complete blood count (CBC), comprehensive metabolic panel (CMP), thyroid stimulating hormone (TSH), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and stool studies, as the most recent and highest quality study suggests that these tests are essential in identifying common causes of chronic diarrhea 1.
Key Laboratory Tests
The following laboratory tests are recommended:
- Complete blood count (CBC) to rule out anemia, infection, or inflammation
- Comprehensive metabolic panel (CMP) to evaluate electrolyte imbalance, kidney function, and liver function
- Thyroid stimulating hormone (TSH) to assess thyroid function
- C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) to evaluate inflammation
- Stool studies, including:
- Fecal calprotectin to assess inflammation in the gut
- Stool culture for bacterial pathogens, such as Salmonella, Shigella, and Campylobacter
- Ova and parasite examination to rule out parasitic infections
- Clostridioides difficile toxin testing to diagnose C. difficile infection
- Fecal occult blood test to detect gastrointestinal bleeding
Celiac Disease Screening
Additionally, celiac disease screening with tissue transglutaminase antibodies (tTG-IgA) and total IgA should be performed, as celiac disease is a common cause of chronic diarrhea and can be effectively managed with a gluten-free diet 1.
Cost-Effective Considerations
For an uninsured patient, consider utilizing community health centers, hospital charity care programs, or diagnostic laboratory patient assistance programs to reduce costs. If these initial tests don't provide a diagnosis, further evaluation with colonoscopy might be necessary, though this would be a second-line approach given the financial constraints.
Rationale
The recommended laboratory workup is based on the most recent and highest quality study, which suggests that these tests are essential in identifying common causes of chronic diarrhea, such as inflammatory bowel disease, celiac disease, microscopic colitis, irritable bowel syndrome, bacterial or parasitic infections, thyroid disorders, and malabsorption syndromes 1.
From the Research
Lab Workup for Chronic Diarrhea
The patient's symptoms of daily diarrhea and lower abdominal pain for one year warrant a comprehensive lab workup to determine the underlying cause.
- A complete blood count, C-reactive protein, anti-tissue transglutaminase immunoglobulin A (IgA), total IgA, and a basic metabolic panel are useful initial tests to evaluate for pathologies such as celiac disease or inflammatory bowel disease 2.
- Stool studies can help categorize diarrhea as watery, fatty, or inflammatory, which can guide further targeted testing 2.
- Specific diagnostic investigation can be reserved for patients with severe dehydration, more severe illness, persistent fever, bloody stools, immunosuppression, and for cases of suspected nosocomial infection or outbreak, and includes:
- Complete blood count
- Creatinine and electrolytes evaluation
- Determination of leukocytes and lactoferrin presence in the stools
- Stool culture
- C. difficile testing
- PCR
- Ova and parasites' search
- Endoscopy and abdominal imaging 3
- The use of a gastrointestinal pathogen panel immunoassay in stool testing can help detect various causative agents of diarrhea, including Clostridioides difficile, norovirus, rotavirus, and Campylobacter spp. 4
Considerations for Patients with Limited Access to Healthcare
For patients lacking health insurance, it is essential to prioritize tests that are most likely to yield a diagnosis and guide treatment.
- A step-wise approach to testing, starting with basic laboratory tests and stool studies, can help minimize costs while still providing valuable diagnostic information 2.
- Clinicians can use clinical and laboratory information to decide which patients are likely to have a specific disease, such as C. difficile colitis, and when it is appropriate to order specific diagnostic tests 5.