Acute gastroenteritis is inflammation of the lining of the stomach and intestine, typically due to an infection. Possible symptoms include abdominal cramps, nausea, diarrhea, and vomiting.

Pathogens such as bacteria and viruses, as well as chemicals, certain foods, and medications, can irritate the lining of the stomach and intestine, causing acute gastroenteritis.

Viral gastroenteritis, which people may call stomach flu, is the most common type. However, the flu virus that causes respiratory infections affecting the nose, throat, and lungs does not cause viral gastroenteritis.

For many people, symptoms resolve within a few days without complications. However, people in high risk categories and those with reduced access to healthcare facilities may experience more severe symptoms.

This article explores the symptoms of acute gastroenteritis. It also discusses acute gastroenteritis causes, treatment, duration, and prevention, as well as when to speak with a doctor.

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According to the National Institute of Diabetes and Digestive and Kidney Diseases, common symptoms of gastroenteritis include:

A person should seek immediate medical attention if they experience any of the following symptoms:

People should also seek urgent medical attention if they experience symptoms of dehydration, which may include:

The pathogens that cause gastroenteritis can spread from person to person or through contact with contaminated food or drinks. A person may also experience acute gastroenteritis as a reaction to certain medications.

Viruses

Viruses are the most common causes of acute infectious gastroenteritis. Viruses that cause gastroenteritis include:

Bacteria

Research suggests that bacterial infections such as Clostridium perfringens and Escherichia coli cause more severe cases of infectious diarrhea than other types of infections that cause acute gastroenteritis.

In the United States, nontyphoidal Salmonella and Campylobacter species are the most common causes of bacterial gastroenteritis.

Parasites

Parasites may spread through soil, food, or water that has been contaminated with feces from animals or humans who carry the parasites. The two species of parasites that most commonly cause parasitic gastroenteritis are Giardia and Cryptosporidium.

Acute gastroenteritis symptoms can last 1–14 days, depending on the cause of the infection. An older source suggests that this is in comparison to persistent gastroenteritis, which lasts 14–30 days, and chronic gastroenteritis, which lasts more than 30 days.

The potential duration may depend on the type of infection that is causing a person’s symptoms. For example:

  • Norovirus: Symptoms begin 12–48 hours after contact and last 1–3 days.
  • Rotavirus: Symptoms begin 48 hours after contact and last 3–8 days.
  • Adenovirus: Symptoms begin 3–10 days after contact and last 1–2 weeks.
  • Astrovirus: Symptoms usually begin 4–5 days after contact and last 1–4 days.

A doctor may recommend the following treatments for acute gastroenteritis:

A person should speak with a healthcare professional before taking any medications to treat acute gastroenteritis.

The following prevention tips may reduce a person’s risk of getting acute gastroenteritis:

  • Always wash hands properly before handling or preparing food and after using the toilet or changing a diaper.
  • Wash all fruits and vegetables before eating them.
  • Avoid eating undercooked foods.
  • Disinfect countertops and other surfaces, clothes, and bedding that may have come into contact with infected stool or vomit.
  • Use rubber gloves while handling clothes and bedding that may have come into contact with infected stool or vomit, and wash hands afterward.

A person should consult a doctor as soon as possible if they or someone in their care is experiencing the following symptoms:

  • high fever in older children and adults, or any fever in infants
  • a change in mental state
  • diarrhea lasting longer than 2 days
  • six or more loose stools in 1 day
  • dehydration symptoms, such as dry mouth and decreased urination
  • frequent vomiting
  • black and tarry stools
  • stools containing blood or pus
  • severe pain in the rectum or abdomen

Acute gastroenteritis is inflammation of the lining of the stomach and intestine. It may result from infections, exposure to certain chemicals, or certain medications.

Common symptoms include vomiting, abdominal cramps, and diarrhea. Symptoms usually resolve within 14 days. A person should seek immediate medical attention if they experience certain symptoms, such as frequent vomiting, changes in their mental state, and high fever.

Treatment may involve replenishing fluids and electrolytes and taking medication according to a healthcare professional’s instructions.