INFECTIONS OF THE SMALL BOWEL

Question 1

What can lead to bacterial overgrowth of the small intestine?

Answer 1

Bacterial overgrowth usually occurs as a result of structural abnormalities which leads to stasis (eg strictures or diverticulae) or where the caecal valve has become insufficient.

Question 2

What are the bacteria normally found in the terminal ileum?

Answer 2

Certain faecal bacteria eg E. coli, enterococcus and Bacteroides

Question 3

What are the clinical features of bacterial overgrowth of the small intestine?

Answer 3

Deconjugation of bile salts by bacteria leads to fat malabsorption and deficiency of fat soluble vitmamins A, D, A and K. Can also metabolise B12.

Causes steatorrhoea and deficiencies of vitamin, especially B12 (anaemia)
Diarrhoea is often presenting complaint.

Question 4

What investigations should be ordered for someone with suspected bacterial overgrowth of the small intestine?

Answer 4

Hydrogen breath test - using oral lactulose or glucose which are metabolised by bacteria to hydrogen. Not very specific test due to oral bacteria.

14C glycocholic acid breath test - C14 bile salt ingested. Bacteria will deconjugate releasing 14CO2

Small intestine aspiration - cultures

Question 5

How would you managed someone with bacterial overgrowth of the small intestine?

Answer 5

Prolonged cyclical courses of metronidazole, tetracycline and ciprofloxacin.
Replace vitamin deficiencies
Treat underlying cause

Question 6

What is Whipple’s disease?

Answer 6

An infection of the small intestine caused by Tropheryma whippelii (a bacteria) - may involve at type of immunodeficiency.

Question 7

What are the features of Whipple’s disease?

Answer 7

Steatorrhoea
Abdominal pain
Fever
Weight loss
Peripheral lymphadenopathy
Migratory arthritis
Pigmentation
Chronic encephalitis if brain is involved

Question 8

How do you treat Whipple’s disease?

Answer 8

Prolonged antibiotics such as penicillin, tertacyclin or chloramphenicol.
Supplement vitamins and minerals