What is the recommended workup, including stool studies, for a young male with clinical presentation and imaging concerning for Inflammatory Bowel Disease (IBD)?

Comprehensive Workup for Young Male with Suspected Inflammatory Bowel Disease

The recommended workup for a young male with imaging and clinical presentation concerning for IBD should include a complete blood count, inflammatory markers, comprehensive stool studies to rule out infectious causes, and colonoscopy with ileoscopy and biopsies as the gold standard for diagnosis. 1

Initial Laboratory Evaluation

• Complete blood count (CBC) - To assess for anemia, leukocytosis, and thrombocytosis
• Inflammatory markers:
  • C-reactive protein (CRP)
  • Erythrocyte sedimentation rate (ESR)
• Comprehensive metabolic panel:
  • Liver function tests
  • Albumin (to assess for malnutrition/protein loss)
  • Electrolytes
• Iron studies - To evaluate iron deficiency anemia

Essential Stool Studies

• Stool for infectious pathogens:
  • Bacterial culture
  • Ova and parasites examination
  • Clostridium difficile toxin assay 1
• Fecal calprotectin - Highly sensitive marker of intestinal inflammation
• Fecal lactoferrin - Another marker of neutrophil activity in the intestine
• Hemoccult testing - To detect occult blood 1

Endoscopic Evaluation

• Colonoscopy with ileoscopy - Gold standard for diagnosis 1

  • Complete visualization of the colon
  • Terminal ileal intubation is essential
  • Multiple biopsies from inflamed and non-inflamed areas
  • Biopsies should be taken from at least five sites including ileum and rectum

• Upper endoscopy - Consider in patients with upper GI symptoms or to help differentiate between Crohn's disease and ulcerative colitis 1

Cross-Sectional Imaging

• MR enterography - Preferred first-line imaging modality 1

  • Evaluates small bowel involvement
  • Detects complications (strictures, fistulae, abscesses)
  • No radiation exposure (important for young patients)

• CT enterography - Alternative when MRI is unavailable 1

  • Similar diagnostic accuracy to MRI
  • Disadvantage of radiation exposure

• Ultrasound - Useful initial screening tool 1

  • Non-invasive and radiation-free
  • Particularly good for terminal ileum assessment
  • Limited by operator dependence and bowel gas

Additional Considerations

• Serologic markers:

  • Anti-Saccharomyces cerevisiae antibodies (ASCA) - Associated with Crohn's disease
  • Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) - Associated with ulcerative colitis

• Capsule endoscopy - Consider if small bowel Crohn's disease is suspected and other imaging is negative 1

  • Patency capsule should be used first to ensure no strictures

Diagnostic Algorithm

1. Initial assessment:

   • Laboratory tests (CBC, CRP, ESR, metabolic panel)
   • Stool studies to rule out infectious causes

2. Endoscopic evaluation:

   • Colonoscopy with ileoscopy and biopsies

3. Cross-sectional imaging:

   • MR enterography (preferred) or CT enterography

4. Additional testing based on findings:

   • Upper endoscopy if upper GI symptoms present
   • Capsule endoscopy if small bowel involvement suspected but not confirmed

Common Pitfalls to Avoid

• Incomplete evaluation: Failure to perform ileoscopy during colonoscopy may miss terminal ileal disease
• Inadequate biopsies: Multiple biopsies from both inflamed and non-inflamed areas are essential
• Premature diagnosis: Failure to exclude infectious causes before diagnosing IBD
• Overreliance on imaging: Cross-sectional imaging should complement, not replace, endoscopic evaluation
• Misclassification: Avoid premature classification as Crohn's disease or ulcerative colitis without sufficient evidence 1

By following this comprehensive approach, clinicians can accurately diagnose IBD, determine disease extent, identify complications, and guide appropriate treatment decisions to improve morbidity, mortality, and quality of life outcomes.