Last reviewed: 24 Jan 2021
Last updated: 31 May 2018



History and exam

Key diagnostic factors

  • presence of risk factors
  • diarrhoea
  • nausea and vomiting

Other diagnostic factors

  • abdominal pain
  • bloating
  • fever
  • dehydration
  • blood or mucus in stool
  • profuse rice-water stool
  • reactive arthritis
  • skin rash
  • difficulty swallowing
  • diplopia
  • slurred speech
  • weakness
  • hepatobiliary disease
  • pulmonary symptoms
  • other intestinal features
  • manifestations of ectopic infection

Risk factors

  • older people, children, and pregnant women
  • chronic disease
  • recent hx of travel
  • immunocompromised state
  • hx of contact with cases of food poisoning
  • consumption of undercooked meat
  • consumption of raw seafood
  • consumption of homemade canned foods
  • consumption of unpasteurised soft cheeses
  • consumption of deli meats
  • consumption of unpasteurised milk or juice
  • consumption of raw eggs
  • improper food handling and storage
  • use of antacids

Diagnostic investigations

1st investigations to order

  • stool microscopy for WBC and red blood cells (RBC)
  • stool culture
  • stool O+P
  • FBC with differential
  • serum creatinine and electrolytes

Investigations to consider

  • stool/serum botulinum toxin detection test
  • blood culture
  • amylase and lipase
  • LFTs
  • hepatitis A IgM antibodies
  • hepatitis E IgM antibodies
  • acute abdominal series
  • sigmoidoscopy/colonoscopy
  • oesophagogastroduodenoscopy
  • biopsy
  • duodenal aspirate

Emerging tests

  • polymerase chain reaction (PCR) of stool

Treatment algorithm


Consultant Gastroenterologist

Department of Gastroenterology

John Radcliffe Hospital




PA is a consultant for Abbvie and an advisor to Bresmed Health Solutions, and has received travel expenses from NPS Pharmaceuticals (now Shire).

Consultant Gastroenterologist

Department of Gastroenterology

John Radcliffe Hospital




SK declares that he has no competing interests.

Dr Philip Allan and Dr Satish Keshav would like to gratefully acknowledge Dr Michael Bennish, Dr Willem J.S. de Villiers, and Dr Houssam E. Mardini, the previous contributors to this topic. MB has received funds, salary, and/or research funding greater than 6 figures USD.


MB declares that he has no other competing interests. WJSDV and HEM declare that they have no competing interests.

Peer reviewersVIEW ALL

Professor of Clinical Microbiology

Austrian Agency for Health and Food Safety (AGES)




FA declares that he has no competing interests.

Department Head

Naval Health Research Center

San Diego



NCC declares that she has no competing interests.

Use of this content is subject to our disclaimer