- The etiology of infectious diarrhea includes bacteria, viruses, and protozoans. Viral infections are the leading cause of diarrhea in the world.
- The common pathogens responsible for watery diarrhea are norovirus and enterotoxigenic Escherichia coli. The pathogens that produce dysentery or bloody diarrhea are Shigella spp., Campylobacter jejuni, nontyphoid Salmonella, and enterohemorrhagic E. coli.
- Fluid and electrolyte replacement is the cornerstone of therapy for diarrheal illnesses. Oral rehydration therapy is preferred in most cases of mild and moderate diarrhea.
- Antibacterial therapy often is not indicated for gastroenteritis because many cases are mild and self-limited or are viral in nature. Antibiotic therapy is recommended in severe cases of diarrhea, moderate-to-severe cases of traveler’s diarrhea, most cases of febrile dysenteric diarrhea, and culture-proven bacterial diarrhea.
- Loperamide offers symptomatic relief in patients with moderate watery diarrhea. However, the use of antimotility agents should be avoided in patients with dysentery diarrhea.
- Diarrheal illness can be largely prevented by following simple rules of personal hygiene and safe food preparation.
- Metronidazole is the drug of choice for mild to moderate Clostridium difficile infection (CDI). In patients with severe disease, contraindication or intolerance to metronidazole, and inadequate response to metronidazole, oral vancomycin or fidaxomicin, is recommended.
- The most common pathogens for traveler’s diarrhea include enterotoxigenic E. coli, Shigella, Campylobacter, Salmonella, and viruses.
- Patient education in prevention strategies and self-treatment of traveler’s diarrhea is recommended. Prophylaxis with antibiotics is not recommended in most situations.
- Common pathogens responsible for food poisoning include Staphylococcus, Salmonella, Shigella, and Clostridium.
On completion of this chapter, the reader will be able to:
Define and distinguish between watery diarrhea and dysenteric diarrhea.
Discuss the common clinical presentations of GI infections.
Describe the typical microbiology of GI infections.
Describe the appropriate indications for stool culture and its limitations.
Assess the degree of dehydration based on clinical presentation.
Choose the method of rehydration therapy based on dehydration status.
Recommend antibiotic therapy for GI infections.
Provide recommendation on the proper duration of treatment of GI infections given details of the patient condition and type of infection.
Describe the rationale and indication for antimotility agent use in diarrheal illnesses.
Describe the proper assessment of patients during treatment of GI infections.
Recommend prevention and treatment strategies for GI infections.
Outline a treatment strategy for C. difficile–related pseudomembranous colitis.
Identify the appropriate patient population and clinical situation in which antibiotics should be used for the treatment of traveler’s diarrhea.
Outline a prevention strategy for traveler’s diarrhea.
Describe the temporal timing relationships of bacterial causes of food poisoning and the severity and onset of symptoms.
GI infections and enterotoxigenic poisonings encompass a wide variety of medical conditions characterized by inflammation of the GI tract. Vomiting and diarrhea are commonly associated with GI inflammation. The resulting dehydration is responsible for much of the morbidity and mortality. Diarrhea is defined as a decrease in consistency of bowel movements (i.e., ...