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Gastroenteritis

Child looking ill on couch

What is gastroenteritis?

Gastroenteritis is an infection or irritation of the gastrointestinal tract that commonly results in abdominal pain, diarrhea and/or vomiting. It may also be called food poisoning, traveler’s diarrhea, stomach flu, or intestinal flu.

Gastroenteritis can affect any age but is particularly common in children. Outbreaks of viral gastroenteritis can also occur regularly in places where a lot of people gather, such as cruise ships, college dormitories, daycare centers, or nursing homes. Anyone with a weakened immune system, such as those with cancer, HIV/AIDS, or taking certain medications (such as regular steroids) are also at higher risk of gastroenteritis.

What causes gastroenteritis?

There are several different causes of gastroenteritis; however, the most common ones include:

  • Viruses, especially rotavirus in children or norovirus (a common cause of gastroenteritis in cruise ships)
  • Bacteria, especially Campylobacter, Escherichia coli (E. coli), or salmonella
  • Parasites, such as Giardia

Gastroenteritis is very contagious as the microbes that cause it are easily spread through contaminated food or water or person-to-person contact. Some viruses can be transmitted via infected droplets suspended in the air that are breathed in or through contaminated surfaces that are touched.

What are the symptoms of gastroenteritis?

Symptoms may develop within one to a few days after infection.

Symptoms of gastroenteritis vary in severity but may include:

  • Abdominal pain
  • Cramping
  • Dehydration
  • Diarrhea (watery, urgent, frequent, and sometimes explosive bowel movements)
  • Headache
  • Fecal incontinence (loss of control over bowel motions)
  • Loss of appetite
  • Mild fever and chills
  • Muscle aches and general body aches
  • Nausea and/or vomiting
  • Poor feeding in infants
  • Tiredness and general body weakness

Symptoms usually last one to two days but may persist for up to ten days. Ring your doctor for advice first before going in for an appointment if you are worried about your condition because gastroenteritis is very contagious and risk spreading it to others.

Always talk to your doctor if your symptoms have lasted longer than five days or have got worse, not better.

Other reasons to see your doctor include:

  • Blood or pus in your stools
  • Constant abdominal pain
  • Significant signs of dehydration such as extreme thirst, dark or strong-smelling urine or passing only small amounts of urine, dry lips and mouth, a lack of tears, your skin fails to retract back when pinched, or if you feel extremely lethargic

Infants are particularly prone to dehydration and you should seek further advice if their nappies have been dry for longer than 4 to 6 hours or if they develop a sunken fontanel (the soft spot on the top of your baby’s head).

How is gastroenteritis diagnosed?

Gastroenteritis is usually just diagnosed by the presence of typical symptoms, for example, having abdominal pain, diarrhea and vomiting together is enough to make the diagnosis of gastroenteritis.

Further testing is usually only conducted if symptoms are severe or persistent and may include stool samples to identify the cause.

How is gastroenteritis treated?

Gastroenteritis may be treated with rest, fluids, and some dietary restrictions until symptoms resolve. For example:

  • Limit your intake of solid foods (this allows your stomach to settle)
  • Avoid sugary, fatty or highly seasoned foods, instead eat bland, dry foods such as crackers, toast, rice or potatoes
  • Take frequent small sips of liquid (thin broths, soups, diluted non-caffeinated drinks, and electrolyte replacement solutions)
  • Avoid alcohol, caffeine, and dairy products
  • Stop smoking or using products containing nicotine
  • Avoid taking medications that may irritate your stomach further such as NSAIDs (eg, aspirin, ibuprofen, diclofenac). Acetaminophen may be used instead, but sparingly
  • Continue breastfeeding if your baby has gastroenteritis and talk to your doctor about offering them rehydration solutions or regular formula

Consider anti-diarrhea medications (eg, loperamide) to slow the diarrhea.

Antibiotics are generally not given for most cases of gastroenteritis because they are ineffective if a virus is the cause and contribute to the development of antibiotic-resistant strains of bacteria.