Diarrhoea Flashcards
What’s the most common cause of Gastro-enteritis
Viruses, with Campylobacter being the commonest bacterial cause
Commonest food poisoning pathogen?
Campylobacter
What pathogen causes the most Hospital admissions
Salmonella
3 catagories of Diarrhoeal illnes
Non-inflammatory/secretory
Inflammatory
Mixed Picture
Clinical features of non-inflammatory diarrhoea + treatment + responsible organisms
Frequent watery stools, with little abdo pain
Rehydration mainstay of therapy
E. coli and Cholera
What is increased in Cholera
cAMP levels and Cl secretion
Clinical features of inflammatory diarrhoea + treatment + responsible organisms
Pain + fever, inflammatory toxin damage + muscoal destruction
Antimicrobials MAY be appropriate but rehydration is often sufficient.
Bacterial infection / amoebic dysentery
What organism is likely responsible for mixed diarrhoeal symptoms
C. difficile
How to assess a patient with diarrhoea
Symptoms + duration (>2wk hx UNLIKELY to be infective gastro-enteritis
Risk of food poisoning (Diet, contact, travel hx)
Assess Hydration (postural BP, skin turgor, pulse)
Features of inflammation (Fever, raised WCC, ?CRP?)
How severe can fluid loss be and what Hypos are asscoiate with it
1-7L/day
Hyponatraemia, due to sodium loss with fluid replacement with hypotonic solutions
Hypokalaemia, due to K loss in stool
Investigations to be carried out
Stool + blood culture
Renal function
FBC (neutrophilia, haemolysis)
Abdo x-ray (if abdo is distended + [?tender?])
Diff diagnosis for diarrhoea
IBD
Spurious diarrhoea (secondary to constipation)
Carcinoma
What may cause diarrhoea that has no relation to the GI tract (would also be part of your diff diagnosis)
Diarrhoea + fever can occur with SEPSIS OUTSIDE THE GUT
- Lack of abdo pain/tenderness goes against gastroenteritis
- no blood/mucus in stools
Treatment for Gastroenteritis
IV (saline) or Oral (salt/sugar solution) Rehydration
Clinicial features of Campylobacter Gastroenteritis
Up to 7 day incubation (dietary hx may be unreliable)
Abdo pain can be severe
Can cause Guillain-Barre syndrome and reactive athritis post infection
Clinical features of Salmonella Gastroenteritis
Symptoms usually onset <48hrs post exposure
Diarrhoea usually lasts <10 days
Post-infective irritable bowel is common
Prolonged carriage may be asscociated with gallstones
Clinical features of E. coli 0157 infection
Frequent BLOODY stools
E. coli stays in gut but toxin gets into the blood
Toxin can cause Haemolytic-uraemic Syndrome (HUS)
Symptoms of HUS
Haemolytic anaemia
Renal Failure
Thrombocytopenia
Treatment for HUS
Supportive
ANTIBIOTICS NOT INDICATED
When are antibiotics indicated in Gastroenteritis
Immunocompromised Severe sepsis or invasive infection Valvular heart disease Diabetes Chronic illness
When are antibiotics NOT indicated in Gastroenteritis
Healthy patient with NON-invasive infection
Clinical features of C. difficile diarrhoea
Usually hx of atibiotic treatment with 4C’s (Clindamycin, Cephalosporins, Co-amoxiclav and Ciprofloxacin)
Severity ranges from mild diarrhoea to severe colitis
Treatments for C. diff
STOP PRECIPATING ANTIBIOTIC (if possible) Oral Metronidazole (if no severity markers) Oral Vancomycin (if 2 or more severity markers)
Fidaxomicin (new + expensive)
Stool transplant
Surgery
Causes of Viral diarrhoea
Adenovirus
Rotavirus in children under 5yrs
When is viral diarrhoea more common
Winter
How is viral diarrhoea diagnosed
Antigen detection
Common cause of viral diarrhoea outbreaks
Norovirus (very infectious)
common in hospitals, small communities and cruise ships.
How is Norovirus diagnosed
PCR
