Overview
Definition
A type of Inflammatory Bowel Disease (IBD) characterized by transmural inflammation that can affect any part of the gastrointestinal tract from the mouth to the perianal area.
Epidemiology
Bimodal age distribution (peaks at 15-30 years and 50-70 years). Strong genetic component.
Etiology & Risk Factors
- Unknown exact cause; thought to be an inappropriate immune response to intestinal flora in genetically susceptible individuals (e.g., NOD2 mutations).
Clinical Symptoms
- Abdominal pain (often Right Lower Quadrant, mimicking appendicitis due to terminal ileum involvement)
- Chronic diarrhea (often non-bloody, unless colon is heavily involved)
- Weight loss and fatigue
- Perianal disease (fistulas, fissures, abscesses)
- Aphthous mouth ulcers
Clinical Approach
Diagnosis
- Colonoscopy with ileoscopy: 'Skip lesions' (patchy inflammation), cobblestone mucosa, aphthous ulcers
- Biopsy: Non-caseating granulomas (hallmark, but not always present), transmural inflammation
- CT/MR Enterography (to evaluate small bowel for strictures/fistulas)
Management
- Induction: Systemic or topical Corticosteroids (Budesonide for ileal disease)
- Maintenance: Immunomodulators (Azathioprine, Methotrexate) or Biologics (Anti-TNF like Infliximab/Adalimumab, Anti-integrin like Vedolizumab)
- Surgery is NOT curative (reserved for complications like bowel obstruction or abscesses)
Complications
- Fistulae (enteroenteral, enterovesical, enterocutaneous)
- Strictures and small bowel obstruction
- Malabsorption (Vitamin B12 deficiency from terminal ileum damage)
- Increased risk of colorectal cancer