Food poisoning

Last reviewed: 26 Aug 2023
Last updated: 02 Aug 2023



History and exam

Key diagnostic factors

  • diarrhea
  • nausea and vomiting
More key diagnostic factors

Other diagnostic factors

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

Risk factors

  • older people, children, and pregnant women
  • chronic disease
  • recent history of travel
  • immunocompromised state
  • history of contact with cases of food poisoning
  • consumption of undercooked meat
  • consumption of raw seafood
  • consumption of homemade canned foods
  • consumption of unpasteurized soft cheeses
  • consumption of deli meats
  • consumption of unpasteurized milk or juice
  • consumption of raw eggs
  • improper food handling and storage
  • gastric acid suppression
More risk factors

Diagnostic investigations

1st investigations to order

  • stool microscopy for WBC and red blood cells (RBC)
  • stool culture
  • stool O+P
  • CBC with differential
  • basic metabolic panel
More 1st investigations to order

Investigations to consider

  • stool/serum botulinum toxin detection test
  • blood culture
  • serum lipase or amylase
  • LFTs
  • hepatitis A IgM antibodies
  • hepatitis E IgM antibodies
  • acute abdominal series
  • sigmoidoscopy/colonoscopy
  • esophagogastroduodenoscopy
  • biopsy
  • duodenal aspirate
  • polymerase chain reaction (PCR) of stool
More investigations to consider

Treatment algorithm


mild to moderate disease

severe disease

suspected foodborne botulism


known infecting organism



Philip Allan, MBBS, DPhil, FRCP

Consultant Gastroenterologist

Department of Gastroenterology

John Radcliffe Hospital




PA has consulted for Takeda (Shire) and BaxterHealthcare. PA has received travel, accommodation, and conference fees from Takeda (Shire).


Dr Philip Allan would like to gratefully acknowledge Dr Satish Keshav, Dr Michael Bennish, Dr Willem J.S. de Villiers, and Dr Houssam E. Mardini, the previous contributors to this topic. Unfortunately, we have been made aware that Dr Satish Keshav has passed away.


MB 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 reviewers

Franz Allerberger, MD, MPH

Professor of Clinical Microbiology

Austrian Agency for Health and Food Safety (AGES)




FA declares that he has no competing interests.

Nancy Crum-Cianflone, MD, MPH

Department Head

Naval Health Research Center

San Diego



NCC declares that she has no competing interests.

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