28-Year-Old Man With Nausea, Vomiting, and Diarrhea

Nicolas Grundmann, MD, MBA


June 10, 2015

The following are three important elements of the history clinicians should consider while trying to determine the differential diagnosis of foodborne diseases:

  • Presenting symptoms;

  • Exposure to a particular type of food associated with foodborne disease—determine what the person ate in the week before they became sick; and

  • The interval between exposure to the suspect food and the onset of symptoms.

The most frequent presentation of a foodborne disease is a combination of nausea, vomiting, fever, abdominal pain, and diarrhea. Nongastrointestinal foodborne illnesses (eg, botulism, ciguatera/scombroid fish) present with a wide variety of clinical pictures. Symptoms concerning for more serious infection include signs of dehydration, bloody stools, fever, and severe abdominal pain.

Diarrhea is an important distinguishing factor for causes of foodborne illness. A lack of diarrhea may suggest that the patient presented early in the course of the disease, the pathogen they ingested was a preformed toxin, or another disease process is occurring (eg, chemical poisoning, bowel obstruction, gastroparesis, gastritis). Bloody diarrhea is a sign of an invasive pathogen and should increase the suspicion for hemorrhagic Escherichia coli, Shigella, Campylobacter, and Salmonella infection with treatment modalities adjusted accordingly.

If a specific food exposure is identified, then the interval between exposure and symptom onset can help determine the etiology of the organism. Broadly, the natural disease process of foodborne pathogens can be divided into three subcategories: preformed toxins, pathogens that produce toxins once ingested, and invasive pathogens.

Preformed toxins are organisms that generate a toxin while growing in the food before its consumption. These are associated with a rapid onset of symptoms (6-12 hours) and are predominantly associated with frequent emesis and only sometimes involve diarrhea. Pathogens that make toxins once they have been ingested usually cause symptoms around 24 hours after exposure and are associated with watery or bloody diarrhea.

Invasive pathogens are microbes that damage the epithelial cell surface directly or invade across the intestinal epithelial cell barrier. These pathogens produce a wide spectrum of clinical presentations, from watery diarrhea to inflammatory diarrhea or systemic disease.


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