Gastroenteritis

Acute viral gastroenteritis

Antimicrobial therapy seldom indicated unless systemic invasion is suspected. Consult Microbiology before starting antibiotics.

Acute bacterial gastroenteritis

In the presence of bloody diarrhoea, consider the possibility of infection with E. Coli 0157. Unless the patient is septic, antibiotics are not appropriate for bloody diarrhoea because of the risk of precipitating Haemolytic Uraemic Syndrome.  Seek microbiologist advice.

Obtain travel history for all cases.

Initial management is supportive until a pathogen has been isolated.

Give empirical antibiotic treatment if:

  • Confirmed or suspected sepsis
  • Age <6 months
  • Immunocompromised
  • Malnourished
  • Haemoglobinopathy and suspected Salmonella gastroenteritis

Those with bacteraemia will require prolonged IV therapy.  Discuss with microbiology.

Treatment

Salmonella

Cefotaxime IV

Duration: 10-14 days

Shigella / Campylobacter

Ciprofloxacin oral

Duration: 5 days

Enteric fever (typhoid and paratyphoid)

Beware of complications e.g. osteomyelitis, meningitis. If these present, treatment should be given for longer.

Seek Microbiologist advice

Treatment

Cefotaxime IV

Treat bacteraemia and severe infection treat for 10-14 days.

Clostridium difficile

Stop all concurrent antibiotics if possible. Seek microbiology advice if antibiotics cannot be stopped.

Mild or moderate:

Metronidazole PO

Duration: 10 to 14 days. Stop at day 10 if symptoms resolved

Severe:

As indicated by any of the following:

  • Immunocompromised
  • Abdominal tenderness
  • Fever
  • Raised WCC
  • Declining renal function
Vancomycin PO

Duration: 10 to 14 days. Stop at day 10 if symptoms resolved.

If patient unable to tolerate oral or NG vancomycin, give Metronidazole intravenously

Do not use Vancomycin IV

Pseudomembranous colitis

Seek urgent GI or surgical review

Vancomycin PO (high dose)

Plus

Metronidazole IV

Peritonitis and SBP  

Peritonitis (community or hospital acquired)

Concomitant surgical management is important.

Patients with complicated peritonitis, previously treated with broad-spectrum antibiotics are at risk of infection with multi-resistant organisms.

In addition empirical antifungal therapy (e.g. fluconazole) may be considered for patients with complicated postoperative intra-abdominal infections.

Treatment

Cefotaxime IV

Plus

Metronidazole IV

If true penicillin allergy: Seek Microbiology advice

Duration: Minimum 7 days

Spontaneous bacterial peritonitis in pre-existing liver disease

Seek urgent surgical and GI review

In patients with liver disease and ascites consider peritoneal tap and send aspirate for urgent microscopy and culture. Prophylaxis may be required after treatment of infection. Seek GI advice

Treatment

Cefotaxime IV

Plus

Metronidazole IV

If true penicillin allergy: Seek Microbiology advice 

Peritonitis associated with dialysis: Seek specialist advice

Cholangitis / cholecystitis

The role of antibiotics in uncomplicated acute cholecystitis remains unclear.

If not improving, consider adding gentamicin and seek microbiology advice.

Treatment

Cefotaxime IV

Plus

Metronidazole IV

Duration: 7-10 days

If true penicillin allergy: Seek Microbiology advice