Small Bowel Bacterial Overgrowth

Disorder of excessive bacterial growth in the small intestine

Aetiology

Causative organisms

  • E. coli
  • Bacteroides

Risk factors

  • Dysmotility - absence/impairment of the migrating motor complex
  • Anatomical disturbances in the bowel
    • Fistulae
    • Diverticula
    • Blind loops created after surgery
    • Resection of the ileo-cecal valve
  • Gastroenteritis-induced alterations to the small intestine
  • Certain medications, including proton pump inhibitors
  • Disorders of the immune system

Clinical presentation

  • Loss of appetite
  • Bloating
  • Diarrhoea
  • Malnutrition
  • Abdominal pain

Investigations

Endoscopy

  • Anatomical disturbances visible (diverticula, fistulas, strictures etc.)
  • Functional stasis

Bloods

  • Low cobalamin (Schilling test)
  • High folate levels

Management

  • Surgical correction of anatomical blind loop if relevant
  • Tetracyclines 2-3 weeks