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  • imageInfectious diarrhea is a disease that causes significant morbidity and mortality worldwide. Its etiology includes various bacteria, viruses, and protozoans, with viral causes being most predominant globally.

  • imageTwo types of infectious diarrhea include watery or enterotoxigenic diarrhea and dysentery or bloody diarrhea. Common pathogens responsible for watery diarrhea are viruses and enterotoxigenic Escherichia coli. Common pathogens responsible for dysentery diarrhea are Shigella spp., Campylobacter jejuni, nontyphoid Salmonella, and enterohemorrhagic E. coli.

  • imageFluid and electrolyte replacement is the cornerstone of therapy for diarrheal illnesses. Oral rehydration therapy is preferred in most cases of mild and moderate diarrhea.

  • imageThe use of antibacterial therapy for infectious diarrhea is not commonly indicated due to the mild and self-limited nature of the infection, or viral etiology. Antibiotic therapy is recommended in cases of severe diarrhea, moderate-to-severe cases of traveler’s diarrhea, most cases of febrile dysenteric diarrhea, and culture-proven bacterial diarrhea in high-risk patients.

  • imageLoperamide and diphenoxylate/atropine may offer symptomatic relief in patients with moderate watery diarrhea; however, use of antimotility agents should be avoided in patients with watery and dysentery diarrhea.

  • imageDiarrheal illness can be largely prevented by procedures to prevent contaminated food or water supplies and with appropriate personal hygiene.

  • imageOral vancomycin or fidaxomicin are recommended as the initial therapy for patients with Clostridioides difficile infection.

  • imageCommon traveler’s diarrheal pathogens include enterotoxigenic E. coli, Shigella spp., Campylobacter spp., Salmonella spp., and viruses.

  • imagePatient education on prevention strategies and appropriate self-treatment of traveler’s diarrhea is preferred, and prophylaxis with antibacterials is not recommended.

  • imagePathogens commonly responsible for food poisoning include Staphylococcus spp., Salmonella spp., Shigella spp., and Clostridioides



Perform a literature search to identify investigational drugs and therapies for Clostridioides difficile infection (CDI) not addressed in the book chapter. Create a document that describes the proposed mechanism of action for each agent.


Gastrointestinal (GI) infections and enterotoxigenic poisonings encompass a wide variety of medical conditions characterized by inflammation of the GI tract. Inflammation-induced vomiting and diarrhea are responsible for much of the morbidity and mortality of these conditions. Diarrhea is defined as a decrease in consistency of bowel movements (ie, unformed stool) and an increase in frequency of stools to three or more per day.1,2 Acute diarrheal disease is commonly associated with diarrhea lasting less than 7 days, prolonged diarrhea lasts 7 to 13 days, persistent diarrhea lasts 14 to 29 days, and chronic diarrhea lasts 30 days or longer.

This chapter focuses on infectious etiologies of acute GI infections and enterotoxigenic poisonings. A wide variety of viral, bacterial, and parasitic pathogens are responsible for these infections. Chapter e138, “Parasitic Diseases,” discusses the common protozoans that cause gastroenteritis. This chapter will focus on pathogenesis and management of common viral and bacterial etiologies. Because the clinical consequences of dysenteric diarrhea ...

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