Intestinal Tuberculosis (ITB)

Definition & Pathogenesis

Intestinal tuberculosis involves infection of the gastrointestinal tract by Mycobacterium tuberculosis, primarily affecting the ileocecal region.

Routes of Infection

• Primary: Direct ingestion of contaminated material
• Secondary: Hematogenous spread from pulmonary TB
• Local spread from adjacent organs
• Through lymphatic channels

Anatomical Distribution

• Ileocecal region (most common - 90%)
• Terminal ileum
• Jejunum
• Colon
• Rectum (rare)

Common Presentations

• Constitutional Symptoms
  • Fever (low-grade, evening rise)
  • Weight loss
  • Fatigue
  • Night sweats
  • Growth failure
• Gastrointestinal Symptoms
  • Chronic abdominal pain (most common)
  • Altered bowel habits
  • Diarrhea alternating with constipation
  • Partial bowel obstruction
  • GI bleeding (rare)

Physical Examination

• Abdominal mass (ileocecal region)
• Ascites
• Peripheral lymphadenopathy
• Signs of malnutrition
• Peritonitis signs in complicated cases

Diagnostic Workup

Laboratory Studies

• Blood Tests
  • Complete blood count
  • ESR and CRP
  • Liver function tests
  • Serum albumin
  • HIV testing
• Microbiological Tests
  • Stool examination for AFB
  • GeneXpert MTB/RIF on tissue samples
  • Culture from tissue specimens
  • PCR for M. tuberculosis

Imaging Studies

• CT Enterography
  • Bowel wall thickening
  • Mesenteric lymphadenopathy
  • Ascites
• MR Enterography
• Barium Studies
  • Pulled-up cecum
  • String sign
  • Ulceration patterns
• Ultrasonography

Endoscopy

• Colonoscopy with biopsy
  • Transverse ulcers
  • Nodularity
  • Strictures
• Capsule endoscopy (if accessible)

Treatment Approach

Medical Management

• Anti-tubercular Therapy
  • Initial Phase (2 months):
    • Isoniazid (H)
    • Rifampicin (R)
    • Pyrazinamide (Z)
    • Ethambutol (E)
  • Continuation Phase (4-7 months):
    • Isoniazid
    • Rifampicin
• Supportive Care
  • Nutritional support
  • Vitamin supplements
  • Probiotics

Surgical Intervention

• Indications:
  • Intestinal obstruction
  • Perforation
  • Fistula formation
  • Non-resolving strictures
• Procedures:
  • Limited resection
  • Strictureplasty
  • Right hemicolectomy

Common Complications

• Acute Complications
  • Intestinal obstruction
  • Perforation
  • Bleeding
  • Acute peritonitis
• Chronic Complications
  • Malabsorption
  • Growth failure
  • Intestinal strictures
  • Fistula formation
  • Adhesions

Prognostic Factors

• Favorable Factors
  • Early diagnosis
  • Good compliance with ATT
  • Absence of complications
  • Good nutritional status
• Poor Prognostic Factors
  • Delayed diagnosis
  • Multiple strictures
  • Perforation
  • HIV co-infection

Follow-up Care

• Regular monitoring of symptoms
• Serial growth measurements
• Nutritional assessment
• Surveillance endoscopy if needed