Infectious diarrhea

What Is Infectious Diarrhea?

Infectious diarrhea is a type of diarrhea and intestinal infection that is caused by a virus, bacteria, or parasite. It is a very common illness, and the most common cause is a type of bacteria called Escherichia coli (E. coli). Infectious diarrhea can also be caused by other bacteria and viruses, such as Salmonella, Campylobacter, Shigella, and noroviruses.

Signs and Symptoms

The most common symptom of infectious diarrhea is watery stool with abdominal cramps, nausea and vomiting. The illness may last a few days or up to a week. Other signs and symptoms may include:

  • Fever
  • Chills
  • Gas
  • Bloating
  • Headache
  • Fatigue


Infectious diarrhea can lead to dehydration if left untreated. If you are experiencing severe diarrhea with vomiting, you may need medical attention. It is important to drink extra fluids to replace lost liquids and electrolytes. If your symptoms persist for more than a week, or if you have a fever, feverishness, or a weak immune system, you should see a healthcare provider.

In rare cases, infectious diarrhea can cause other serious complications, such as severe dehydration, bloody stools, and nausea or vomiting that does not improve. If you experience any of these symptoms, it’s important to see a doctor right away.


Most cases of infectious diarrhea improve without treatment. Drinking water or electrolyte drinks, such as sports drinks, can help replace lost fluids, minerals, and electrolytes. Over-the-counter medications, such as loperamide (Imodium®) may help with symptoms, but should not be used in children. Antibiotics may be prescribed for some bacterial infections, but are not needed for viral or parasitic infections.

In some cases, hospitalization is needed to prevent dehydration. Hospitalization may also be required for cases involving a weakened immune system, young children, and elderly adults.