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E. coli Gastroenteritis


Jonathan Gotfried

, MD, Lewis Katz School of Medicine at Temple University

Reviewed/Revised Jun 2023

Several different subtypes of Escherichia coli cause diarrhea. The epidemiology and clinical manifestations vary greatly depending on the subtype. When needed, organism-specific diagnosis can be made by polymerase chain reaction testing of stool. Treatment is typically supportive.

E. coli normally inhabit the gastrointestinal tract; however, some strains have acquired genes that enable them to cause intestinal infection. When ingested, the following strains can cause diarrhea:

Symptoms and Signs of E. coli Gastroenteritis

Symptoms of hemorrhagic E. coli are severe abdominal cramps which begin suddenly along with watery diarrhea, which may become bloody within 24 hours. The diarrhea usually lasts 1 to 8 days.

Fever is usually absent or mild but occasionally can exceed 102° F (39° C).

Diagnosis of E. coli Gastroenteritis

  • Sometimes stool testing aimed at Shiga toxin

  • Sometimes stool PCR testing

Stool studies for a bacterial cause are indicated in patients with bloody or heme-positive stool, fever, moderate to severe diarrhea, or diarrhea lasting more than 7 days, in those 70 years old or older, or in those with inflammatory bowel disease or immunocompromising disorders such as HIV/AIDS. Stool studies are also indicated for those at high risk of spreading disease to others (eg, health care, day care, or food service workers) and during known or suspected outbreaks.

A rapid stool assay for Shiga toxin or, when available, a test for the gene that encodes the toxin may be helpful.

Each of the E. coli subtypes can be detected in stool by polymerase chain reaction (PCR) testing, typically using a multiplex PCR panel. Sometimes more than one organism is detected simultaneously, the clinical significance of which is unclear.

Treatment of E. coli Gastroenteritis

  • Oral or IV rehydration

  • Sometimes antibiotics

Supportive care including rehydration with fluids and electrolytes is the mainstay of treatment and is all that is needed for most adults. Oral glucose-electrolyte solutions, broth, or bouillon may prevent dehydration or treat mild dehydration. Children may become dehydrated more quickly and should be given an appropriate rehydration solution (several are available commercially—see Oral Rehydration Oral Rehydration Oral fluid therapy is effective, safe, convenient, and inexpensive compared with IV therapy. Oral fluid therapy is recommended by the American Academy of Pediatrics and the World Health Organization... read more ). Isotonic IV fluids such as Ringer’s lactate and normal saline solution should be given when there is severe dehydration, shock, or altered mental status and ileus or failure of oral rehydration therapy (see also the Infectious Diseases Society of America's [IDSA] 2017 clinical practice guidelines for the diagnosis and management of infectious diarrhea). In severe dehydration, IV rehydration should be continued until pulse, perfusion, and mental status normalize.

Antidiarrheal agents (eg, loperamide) should not be given to children < 18 years of age with acute diarrhea (see the IDSA guidelines). Antidiarrheals are generally safe for adult patients with watery diarrhea (as shown by heme-negative stool). However, antidiarrheals may cause deterioration of patients with Clostridioides difficile or E. coli O157:H7 infection and thus should not be given to any patients with recent antibiotic use, bloody diarrhea, heme-positive stool, or diarrhea with fever, pending specific diagnosis.

Antibiotics given empirically are generally not recommended except when suspicion of Shigella or Campylobacter infection is high (eg, contact with a known case). Otherwise, antibiotics should not be given until stool culture results are known because antibiotics increase the risk of hemolytic-uremic syndrome Hemolytic-Uremic Syndrome (HUS) Hemolytic-uremic syndrome (HUS) is an acute, fulminant disorder characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury. HUS usually occurs in children... read more Hemolytic-Uremic Syndrome (HUS) in patients infected with E. coli O157:H7. Stool culture results are particularly important in children, who have a higher rate of infection with E. coli O157:H7.

The use of probiotics is not recommended for suspected E. coli gastroenteritis (see also the American College of Gastroenterology's 2016 clinical guideline of the diagnosis, treatment, and prevention of acute diarrheal infections in adults and the American Gastroenterological Association's 2020 clinical practice guidelines on the role of probiotics in the management of gastrointestinal disorders).

Key Points

More Information

The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

Drugs Mentioned In This Article

Drug Name Select Trade
Anti-Diarrheal, Imodium A-D, Imodium A-D EZ Chews , K-Pek II, Medique Diamode
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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