Gastrointestinal · Year 2 · from Gastrointestinal
Case 1: Crohn's Disease
Patient Presentation
Demographics: 24-year-old female
Chief Complaint: Chronic diarrhea, abdominal pain, and weight loss for 6 months
History of Present Illness: The patient reports 4-6 loose, non-bloody stools daily with crampy right lower quadrant abdominal pain that partially improves after bowel movements. She has lost 18 pounds over 6 months. She has developed a painful perianal lesion that is draining purulent material. She also reports joint pain in her knees and ankles and has noticed painful mouth sores.
Past Medical History: None
Family History: Uncle has "bowel disease" requiring multiple surgeries
Social History: Non-smoker, occasional alcohol
Physical Examination
- Vital Signs: BP 108/68 mmHg, HR 92 bpm, Temperature 37.6C, BMI 19
- General: Thin, pale female appearing chronically ill
- Oral: Two aphthous ulcers on buccal mucosa
- Abdomen: Tender fullness in right lower quadrant, no peritoneal signs
- Perianal: Draining perianal fistula at 5 o'clock position
- Musculoskeletal: Bilateral knee effusions, tender ankles
Workup and Results
- CBC: Hemoglobin 10.2 g/dL, WBC 11,200, Platelets 485,000 (reactive thrombocytosis)
- CRP: 48 mg/L (elevated)
- Albumin: 2.9 g/dL
- Fecal Calprotectin: 650 mcg/g (markedly elevated, indicates intestinal inflammation)
- Colonoscopy: Skip lesions with aphthous ulcers, cobblestone mucosa in terminal ileum and cecum; rectal sparing; deep ulcerations in terminal ileum
- MR Enterography: Thickened terminal ileum with mural enhancement and restricted diffusion; small mesenteric abscess (2 cm)
- Histopathology: Non-caseating granulomas, transmural inflammation
Colonoscopic image of Crohn's disease showing characteristic cobblestone mucosa created by linear ulcerations intersecting with areas of edematous mucosa, and deep serpiginous ulcers in the terminal ileum.
Image Source: Wikimedia Commons, CC BY-SA 3.0
Diagnosis
Crohn's Disease (Ileocolonic, Penetrating/Fistulizing Phenotype)
Clinical Correlation
Crohn's disease is a chronic inflammatory condition that can affect any portion of the GI tract from mouth to anus, with terminal ileum most commonly involved. Key distinguishing features from ulcerative colitis include: transmural inflammation (leading to strictures, fistulas, abscesses), skip lesions (non-contiguous involvement), rectal sparing, granulomas on histology, and perianal disease. Extraintestinal manifestations include arthritis (most common), aphthous ulcers, and skin/eye involvement. This patient's perianal fistula and mesenteric abscess indicate penetrating/fistulizing behavior, a more aggressive phenotype.
Treatment
- Mesenteric abscess: CT-guided drainage + antibiotics (ciprofloxacin + metronidazole)
- Perianal fistula: MRI pelvis to characterize; surgical drainage of any abscess; seton placement
- Induction therapy: anti-TNF biologic (infliximab or adalimumab) given fistulizing disease
- Maintenance therapy: continue anti-TNF + consider adding immunomodulator (azathioprine)
- Nutritional support: enteral nutrition, vitamin/mineral supplementation
- Smoking cessation counseling (critical - smoking worsens Crohn's)
- Surveillance for strictures and malignancy