Bacterial Overgrowth of Small Intestine

Bacterial Overgrowth of Small Intestine

·         =Aerobic G+ bacteria replaced by anaerobic G-, esp. E coli & clostridium difficile (toxin causes diarrhoea) often in a blind loop of bowel, or in the small bowel which usually has low bacterial load

·        Symptoms & Signs:

o   Diarrhoea, abdominal pain, weight loss

o   Steatorrhoea, anaemia, ataxia/neuropathy (due to B12 deficiency – bacteria eat it all)

·        Investigations:

o   Blood: check for anaemia, B12, folate

o   Schilling test

o   Stool fat 

o   Barium x-ray for jejunal stricture/diverticulitis, ¯motility

o   Duodenal aspiration and biopsy

·        Differential:

o   Coeliac disease

o   Chronic pancreatitis

o   Crohn‟s disease

o   Infections: campylobacter, Giardia, AIDs enteropathy 

o   Breath tests: ­H2 after lactulose, etc

·        Aetiology

o   Motility disorders

o   ­Bacteria: e.g. ¯stomach acid (hypochlorhydria)

o   Impaired immunity

·        Treatment:

o   High protein diet, vitamin supplementation, stop antibiotics

o   Antibiotics: Metronidazole 400 mg TD, Ciprofloxacin 500 mg BD, or vancomycin