Diagnostic Approach to Crohn's Disease and Gastritis
Essential Stool Studies
- The European Society of Gastrointestinal Endoscopy recommends stool cultures for entero-invasive bacterial infections and stool Clostridioides difficile assay as part of the initial workup for patients with suspected or worsening Crohn's disease or gastritis, with a strength of evidence level of high 1, 2
- Fecal calprotectin helps differentiate IBD from IBS with high sensitivity (93%) and specificity (96%), and is recommended by the American Gastroenterological Association for monitoring disease activity 4
- Fecal lactoferrin aids in differentiating IBD from functional disorders, and is supported by the European Crohn's and Colitis Organisation as a useful biomarker 4
- The American College of Gastroenterology recommends Clostridioides difficile toxin assay, particularly in patients with recent antibiotic use or hospitalization, with a strength of evidence level of strong 1, 3
Special Considerations
- The European Society of Clinical Microbiology and Infectious Diseases recommends CMV testing via colonic biopsies for patients with moderate to severe colitis, particularly those with steroid-refractory disease, with a strength of evidence level of moderate 1, 2
- Vancomycin or fidaxomicin are recommended for 10 days for treating non-severe C. difficile infection, according to the Infectious Diseases Society of America, with a strength of evidence level of high 1, 3
Clinical Pearls and Pitfalls
- Failing to test for C. difficile in all IBD flares can lead to higher rates of colectomy, postoperative complications, and mortality, as highlighted by the American Gastroenterological Association 1
- Escalating immunosuppressive therapy in the setting of undiagnosed C. difficile infection can worsen patient outcomes, and is cautioned against by the European Crohn's and Colitis Organisation 2, 3