Foodborne E coli infection

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Evidence last reviewed: 14 Sep 2026

Topic last updated: 23 Apr 2026

Foodborne Escherichia coliinfection most commonly occurs through the ingestion of food or water contaminated with pathogenic strains of E coli.

Enterotoxigenic E coli (ETEC) is the most common cause of traveler's diarrhea.

Diagnosis is made based on stool culture, with serotyping for greater specificity.

Treatment is supportive, with rehydration and correction of electrolyte imbalance.

Use of antibiotics is controversial and in most cases not necessary, except possibly in traveler's diarrhea.

In the US, the most common serotype of Shiga toxin-producing E coli (STEC), historically referred to as enterohemorrhagic E coli (EHEC), is O157:H7.

Approximately 5% to 10% of patients with E coli O157:H7 infection develop hemolytic uremic syndrome.

Definition

E coli is a gram-negative, rod-shaped bacterium. It is a commensal organism that colonizes the gastrointestinal tract within a few hours of birth. E coli becomes pathogenic by acquiring virulence factors or genetic mutations. Infection by pathogenic strains occurs through ingestion, usually via contaminated food or water.

History and exam

Key diagnostic factors

diarrhea
history of travel, contact with contaminated food, or contact with infected person

Full details

Other diagnostic factors

abdominal pain or discomfort
volume depletion
fever
nausea/vomiting
anorexia
lethargy

Full details

Risk factors

ingestion of contaminated food products or water
travel
poor hygiene practices
infantile or advanced age (<5 years and >65 years)
contact history
immunocompromised state
contact with infected animals

Full details

Diagnostic investigations

1st investigations to order

stool cultures
CBC
renal function and electrolytes

Full details

Investigations to consider

identification of Shiga toxin-producing E coli infection
blood cultures
inflammatory markers (CRP and/or erythrocyte sedimentation rate)
abdominal x-ray
endoscopy
abdominal CT scan

Full details

Treatment algorithm

INITIAL

suspected foodborne illness

ACUTE

confirmed enterotoxigenic positive

confirmed enterohemorrhagic positive

other Escherichia coli serotypes

Contributors

Authors

Eli D. Ehrenpreis, MD, FACG, AGAF

Reaserch Director

Internal Medicine Residency

Advocate Lutheran General Hospital

Park Ridge

Professor of Medicine

Wake Forest University Medical School

Winston-Salem

Disclosures

EDE is CEO, owner, and shareholder for E2Bio Life Sciences LLC. E2Bio Life Sciences LLC has developed Bocaliner, an FDA-registered class 1 medical device designed to enhance the efficacy of topical medications applied to the oral cavity. EDE is the inventor and owner of patents for this device. EDE is also a CEO of G.I. Pharmaceuticals Inc., which has medical treatments for oral leukoplakia designed to prevent oral cancer, and a new medication for anal pruritus. G.I. Pharmaceuticals Inc. is involved with the development of educational programs for students and medical trainees.

Acknowledgements

Dr Eli D. Ehrenpreis would like to gratefully acknowledge the assistance of Dr Olivia Foy, who contributed to this update. Dr Eli D. Ehrenpreis would like to gratefully acknowledge Dr Olivia Foy, Dr Alexandra Kent, and the late Professor Satish Keshav, the previous contributors to this topic.

Disclosures

OF and AK declare that they have no competing interests.

Revisores

Andrew Poullis, BSc, MBBS, MD, FRCP

Consultant Gastroenterologist

St George’s Hospital

London

Declarações

AP declares that he has no competing interests.

Fiona Cooke, MA, PhD, MSc, FRCPath, MRCP, DTM&H

Research Fellow and Medical Microbiologist

Wellcome Trust Sanger Institute

Department of Microbiology

Addenbrooke's Hospital

Cambridge

Declarações

FC declares that she has no competing interests.

Houssam E. Mardini, MD, MPH, FACP

Voluntary Assistant Professor of Medicine

Digestive Health & Nutrition Center of Ashland

Ashland

Declarações

HEM declares that he has no competing interests.

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Principais artigos

Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.Texto completo Resumo

Centers for Disease Control and Prevention. CDC Yellow Book 2026: health information for international travel: preparing international travelers - travelers' diarrhea. 2025 [internet publication].Texto completo

Artigos de referência

Uma lista completa das fontes referenciadas neste tópico está disponível para os usuários com acesso total ao BMJ Best Practice.

Diagnósticos diferenciais
- Viral gastroenteritis
- Alternative foodborne bacterial gastroenteritis/traveler's diarrhea
- Amebiasis
Mais Diagnósticos diferenciais
Diretrizes
- E. coli (Escherichia coli) infection
- Infectious diarrhea - guideline for investigation
Mais Diretrizes
Folhetos informativos para os pacientes
Diarrhea in adults
Diarrhea in children
Mais Folhetos informativos para os pacientes
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Foodborne E coli infection

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Treatment algorithm

suspected foodborne illness

confirmed enterotoxigenic positive

confirmed enterohemorrhagic positive

other Escherichia coli serotypes

Contributors

Authors

Eli D. Ehrenpreis, MD, FACG, AGAF

Disclosures

Acknowledgements

Disclosures

Revisores

Andrew Poullis, BSc, MBBS, MD, FRCP

Declarações

Fiona Cooke, MA, PhD, MSc, FRCPath, MRCP, DTM&H

Declarações

Houssam E. Mardini, MD, MPH, FACP

Declarações

Créditos aos pareceristas

Declarações

Referências

Principais artigos

Artigos de referência

Uma lista completa das fontes referenciadas neste tópico está disponível para os usuários com acesso total ao BMJ Best Practice.

Diagnósticos diferenciais

Diretrizes

Folhetos informativos para os pacientes

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se ou assinar para acessar todo o BMJ Best Practice

Conectar-se para acessar todo o BMJ Best Practice