From the Guidelines
The most appropriate laboratory tests for Inflammatory Bowel Disease (IBD) include a full blood count, electrolytes, liver enzymes, inflammatory biomarkers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), serum albumin, and pre-albumin, as well as fecal calprotectin to assess disease activity and rule out infectious causes 1.
Laboratory Tests for IBD
When assessing a patient with suspected IBD, the following laboratory tests are recommended:
- Full blood count to check for anemia and inflammation
- Electrolytes and liver enzymes to assess overall health and detect any abnormalities
- Inflammatory biomarkers such as ESR and CRP to measure inflammation levels
- Serum albumin and pre-albumin to assess nutritional status and degree of inflammation
- Fecal calprotectin to assess intestinal inflammation and disease activity
Rationale
These laboratory tests are essential in diagnosing and managing IBD, as they help to:
- Assess disease activity and severity
- Monitor response to treatment
- Detect any complications or comorbidities
- Rule out infectious causes of symptoms According to the most recent guidelines, CRP and fecal calprotectin are the most widely used biomarkers for IBD evaluation, with CRP being more sensitive than ESR for evaluating acute abdominal pain in patients with IBD 1.
Additional Considerations
In addition to these laboratory tests, it is also important to consider the following:
- Colonoscopy with biopsies is the gold standard for diagnosing IBD and assessing disease activity
- Imaging studies such as MRI or CT scans may be used to evaluate the extent of disease and detect any complications
- Stool tests to rule out infectious causes of symptoms, such as Clostridium difficile or Cytomegalovirus, should also be considered 1.
From the Research
Laboratory Tests for Inflammatory Bowel Disease (IBD)
The diagnosis and management of IBD rely on a combination of clinical symptoms, laboratory tests, and imaging data. Some of the laboratory tests used to diagnose and monitor IBD include:
- Fecal and blood indicators, which can provide ideas for the prevention, screening, diagnosis, and monitoring of IBD 2
- Nonspecific tests to differentiate diarrhea due to mucosal injury from that occurring in patients with normal bowel mucosa, such as fecal occult blood and leukocytes 3
- Tests to exclude infectious agents, which are important since the clinical and radiological appearance of these may mimic IBD 3
- Tests to assess nutritional status, although "clinical assessment" is as good as the laboratory assessment 3
- Estimation of disease activity by tests, which is rarely better than the judgment of the clinician 3
- Workup for malabsorption in Crohn's disease and the assessment of absorptive capacity of the terminal ileum, which are important for proper planning of management 3
- Laboratory tests to diagnose or prevent complications, such as anemias and joint diseases 3, 4
Biomarkers for IBD
Biomarkers can be used in the diagnosis and management of IBD, but none of them has been proven to be ideal 5. Some of the biomarkers used in IBD include:
- Classical laboratory tools, such as blood and fecal tests 5
- New biomarkers that can discriminate between the types of IBD, predict future responses to treatment, and aid in differential diagnosis, treatment planning, and prognosis prediction 5
- Biomarker signatures, which are emerging as a concept in IBD diagnostic and personalized medicine 5
Imaging Tests for IBD
Imaging tests, such as ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI), can be used to assess the morphological characteristics of IBD, including mucosal alterations, transmural involvement, and extraintestinal manifestations 6. Ultrasound has the advantage of being noninvasive, less costly, and easily repeatable, making it a useful tool for following up patients with IBD 6.