Crohn v TB

Crohn’s disease vs Intestinal Tuberculosis (TB) is a classic diagnostic dilemma, especially in endemic areas. Both conditions affect the ileocecal region, have overlapping clinical, endoscopic, and histologic features — but their treatments are entirely different, so accurate distinction is critical.

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Comparison Table: Crohn’s Disease vs Intestinal TB

Feature	Crohn’s Disease	Intestinal Tuberculosis
Etiology	Idiopathic, autoimmune	Mycobacterium tuberculosis infection
Common Site	Terminal ileum ± colon, skip lesions	Ileocecal region (most common), usually continuous
Onset	Gradual, chronic	Subacute to chronic
Symptoms	Diarrhea, abdominal pain, weight loss, perianal disease	Abdominal pain, weight loss, fever, night sweats
Diarrhea	Often chronic, may be bloody	Less common, non-bloody diarrhea
Fever, Night Sweats	Uncommon	Common
Pulmonary TB history	Rare	Often positive or past TB exposure
Perianal disease	Common (fissures, fistulae, abscesses)	Rare
Endoscopy	Skip lesions, cobblestone appearance, linear ulcers	Transverse ulcers, nodularity, deformed ileocecal valve
Biopsy/Histology	Non-caseating granulomas (deep, rare)	Caseating granulomas (necrosis, large, confluent)
AFB Stain / PCR	Negative	Positive for AFB or TB-PCR
Response to ATT	No response	Good response to anti-tubercular therapy (ATT)
Imaging (CT/MRI)	Asymmetric wall thickening, fistulas, mesenteric fat wrap	Concentric thickening, necrotic nodes, ascites

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Red Flag Differences:

Clue	Suggests…
Caseating granulomas	TB
Perianal disease, fistulas	Crohn’s
Pulmonary TB or contact	TB
Skip lesions	Crohn’s
Transverse ulcers, gaping ileocecal valve	TB
Linear ulcers, cobblestoning	Crohn’s
Dramatic response to ATT	TB

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Best Diagnostic Tests:

• TB-PCR or GeneXpert on biopsy
• AFB stain/culture (low yield but specific)
• Mantoux/IGRA: positive in TB, sometimes in Crohn’s
• CT enterography / MRI enterography
• Therapeutic trial of ATT if still unclear

✅ Summary:

Crohn’s disease is a chronic inflammatory bowel disease; intestinal TB is an infectious disease with overlapping features. Look for caseating granulomas, TB exposure, and systemic signs for TB; and skip lesions, perianal disease, and transmural inflammation for Crohn’s.

Would you like a visual algorithm or diagnostic flowchart to differentiate them step-by-step?