Travellers’ Diarrhoea

Objectives

To support frontline clinicians in preventing, recognising and treating infectious diarrhoea during deployment, minimising operational impact and preventing outbreaks. 

Scope

Covers acute infectious diarrhoea and its complications. Chronic or non‑infectious diarrhoea is excluded and requires referral. Includes outbreak control measures specific to deployed settings. 

Audience

This guideline is intended for use by registered healthcare professionals fulfilling a general role in forward medical locations or in an emergency department in a deployed hospital setting

Initial Assessment & Management

Definition:
≥3 loose stools in 24 h ± vomiting/fever within 14 days of exposure.

Typical Presentation:
Acute onset of ≥3 loose stools in 24 h, often with crampy abdominal pain, nausea/vomiting, and low-grade fever within 14 days of food, water, or contact exposure.

History:

• Itinerary and exposures: street food, unboiled water/ice, sick co-travellers, animals, freshwater
• Recent antibiotics or healthcare contact (risk of C. difficile)
• Sexual exposures
• Comorbidity or immunosuppression

Subacute or relapsing course → consider non-infectious causes (IBD flare) or protozoal infection

Examination:

• Assess hydration status
• Exclude red flags:
  • Dysentery >24hrs
  • Persistent high fever
  • Severe abdominal pain or distension
  • Hypotension or altered consciousness

Exclude surgical/medical mimics as possible with history/examination

Medical Mimics

• Malaria (especially with fever and GI symptoms in endemic areas) → perform rapid diagnostic test (RDT)
• Typhoid/paratyphoid fever → persistent fever, abdominal pain, relative bradycardia
• Acute viral hepatitis → jaundice, dark urine, elevated LFTs
• Inflammatory bowel disease flare → subacute onset, blood in stool, history of IBD
• Medication-related diarrhoea (e.g., antibiotics causing C. difficile, or just antibiotic induced loose stools)

Surgical mimics

• Appendicitis (especially in early stages with diarrhoea and abdominal pain)
• Intestinal obstruction → vomiting, distension, absent bowel sounds
• Peritonitis → severe abdominal pain, guarding, rebound tenderness
• Ischaemic bowel (rare but catastrophic) → severe pain out of proportion to exam, previous history of blood clots, AF. 

Initial Management:

• Oral rehydration (IV crystalloids if unable to tolerate PO); patient likely to be sodium, chloride and potassium deplete if prolonged diarrhoea. monitor urine output.
• Isolation and strict hand hygiene
• Symptom relief: Loperamide 4 mg then 2 mg after each loose stool (max 16 mg/24 h) if satisfied this is uncomplicated watery diarrhoea. Withhold if bloody stool or high fever
• Antibiotics if disease is moderate or severe, prolonged > 3 days, or if evidence of dysentery: 
  • Azithromycin 500 mg PO OD ×3 d

Escalate / Evacuate if:

• Shock or severe dehydration not responding to fluids
• Peritoneal signs
• Ongoing dysentery >24 h
• Failure to maintain oral intake

Advanced Assessment & Management

Patient should be treated according to the principles outlined above. At Role 2/3 the following should be performed in addition: 

• FBC, U&Es (NB sodium, Chloride, potassium), glucose, ABG/VBG for bicarbonate/lactate
• Stool PCR/culture/Ova and parasites if severe disease, immunocompromise, outbreak within contacts, or symptoms >7 days
• C. difficile testing if recent antibiotics/healthcare exposure
• Malaria RDT if febrile after travel to endemic areas

Treatment:

• Oral/NGT/IV fluids guided by electrolytes and urine output
• Start IV antibiotics (e.g. ceftriaxone 1 g IV OD) for severe systemic infection

Complications to consider:

Haemolytic Uraemic Syndrome (HUS):

• Classically follows Shiga toxin–producing E. coli (STEC) diarrhoea (often bloody) and can occur 3–10 days after onset of gastroenteritis.
• Most common in young children, but can affect adults (including older adults)—maintain a high index of suspicion in any patient with dysentery who deteriorates.
• Suspect HUS if: A patient with recent diarrhoea develops the triad of:
  •  anaemia (pallor, raised bilirubin, schistocytes on blood film),
  • thrombocytopenia or bruising seen at role 1, and
  • acute kidney injury (or low urine output at role 1). 
• May also see hypertension, neurological symptoms, and fluid overload.

Investigations:

• FBC
• U&Es/creatinine
• blood film (schistocytes)
• LDH
• bilirubin
• stool PCR/culture for STEC/Shigella

Immediate actions:

• Evacuate urgently and seek specialist advice (paediatric/renal/hepatology via reach‑back).
• Avoid antimotility agents (e.g., loperamide)
• Supportive care:
  • Controlled IV fluids, correct electrolytes, manage hypertension if present, 
  • transfuse RBCs if symptomatic anaemia;
  • avoid platelets unless active bleeding or procedures; this is a consumptive thrombocytopaenia so more platelets will lead to further clots forming is microvasculature, particularly the kidneys and brain.

Prolonged Casualty Care

• Continue electrolyte replacement
• Daily review for complications; particularly delayed complications such as HUS.
• Liaise with Environmental Health & Public Health for outbreak control, FMed 85 for notifiable organisms
• Plan aeromed and discuss with reach back services if haemodynamic instability, sepsis, HUS, or persistent bloody diarrhoea >72 h.  

Paediatric Considerations

The same investigations and supportive principles apply in children. Special considerations are highlighted below: 

Assessment

Management:

• First-line: Oral Rehydration Solution (ORS) - aggressively and early. Offer small, frequent sips; use spoon/syringe if vomiting. ORS will reduce the risk of electrolyte mismanagement with intravenous therapy if tolerated.
• IV fluids if:
  •  shock: 20 mL/kg isotonic crystalloid bolus, reassess
  • Unable to tolerate ORS or ongoing significant losses.

Monitoring: Track electrolytes (Na/K), glucose (treat hypoglycaemia promptly), and urine output.

Antimotility Agents - Avoid loperamide in children <12 years.

HUS Vigilance - Maintain high suspicion in any child with bloody diarrhoea or deterioration 3–10 days after gastroenteritis.

Lower threshold for evacuation in infants/young children due to rapid dehydration and complications.