Symptoms

Symptoms of gastroenteritis usually begin one or two days after infection and include:

• diarrhea
• nausea and vomiting
• headache, muscle aches, or joint aches
• fever or chills
• sweating or clammy skin
• abdominal cramps and pain
• loss of appetite

These symptoms can last anywhere from 1 to 10 days. You should seek emergency medical treatment if:

• diarrhea has lasted for three days or more without getting less frequent
• blood is present in your diarrhea
• you show or see signs of dehydration, such as dry lips or dizziness

In addition to the above symptoms, you should seek emergency attention for your child if they have the appearance of sunken eyes or if they are not making tears when they cry.

Diagnosis

Gastroenteritis is usually diagnosed by the symptoms that it produces, primarily diarrhoea. However, if the symptoms are severe or persistent, your doctor may take a stool (faeces) sample to identify the cause of the gastroenteritis.

Stool samples may be taken during outbreaks of gastroenteritis, such as those occurring on cruise ships and in hospitals and nursing homes, to identify the virus or bacteria that has caused the outbreak. Also, identifying patients with similar histories of food or drink they have recently consumed often helps to determine the source of the outbreak.

Causes

The most common cause of gastroenteritis is a viral or bacterial infection, and less commonly parasitic infection. The most common causes of viral gastroenteritis are norovirus and rotavirus. Escherichia coli (E. coli), Salmonella and Campylobacter are the most common causes of bacterial gastroenteritis. Parasitic gastroenteritis is usually caused by Giardia.

Viral gastroenteritis is the most frequent cause of gastroenteritis outbreaks, which occur when groups of people are affected at the same time and place.

Norovirus outbreaks can affect both children and adults, while rotavirus mainly affects infants and children.

The people most at risk of gastroenteritis are:  

• Infants and young children, who have an immature immune system
• The elderly, who have less efficient immune systems, and especially those living in nursing homes
• Children in day care, school children and students living in dormitories
• Anyone with a weakened immune system, such as people with HIV/AIDS or receiving chemotherapy
• Travellers.  

Prevention

The following actions can be taken to avoid getting and spreading gastroenteritis:  

• Frequent and thorough hand washing, especially before eating or preparing food, and after going to the toilet or contact with an infected person
• Ensure that children wash their hands frequently and thoroughly
• Avoid direct contact with infected individuals, if possible
• Stay home from work and keep children away from day-care or school until symptoms have gone
• Washing the clothing, bedding, and toys of an infected person
• Cleaning and disinfecting kitchen surfaces, especially after working with raw meat or chicken, or eggs
• Avoid eating undercooked foods, especially meat, chicken, and fish
• Avoid drinking untreated water
• Avoid eating raw meats, fish, and shellfish unless you are sure that they have been freshly prepared and are from a reliable source
• Thoroughly wash any fresh produce, such as fruits and vegetables
• Have your infant or child vaccinated with a rotavirus vaccine, which can prevent gastroenteritis caused by rotavirus
• Drink only bottled or boiled water and avoid ice cubes when travelling, especially in developing countries.

Typical treatment 

Most people with gastroenteritis recover within several days without the need for medical treatment, as long as they stay properly hydrated. To help keep yourself comfortable and prevent dehydration while you recover, try the following:  

• Stop eating solid foods to let your stomach settle
• Avoid dairy products, caffeine, alcohol, nicotine
• Avoid sugary, fatty or highly seasoned foods
• Drink plenty of liquid every day, taking small, frequent sips, including clear thin broths or soups, diluted non-caffeinated sports drinks (e.g. Powerade or Gatorade), and rehydration formulas (e.g. Gastrolyte) that are available without prescription from a pharmacy
• Ease back into eating slowly with bland easy-to-digest foods such as, crackers, toast, bananas, rice and potatoes
• Make sure that you get plenty of rest
• Avoid taking non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen, and diclofenac, for pain relief as they can make your stomach more upset
• Paracetamol (e.g. Panadol) can be taken for fever and abdominal pain but it should be used cautiously.

For infants with gastroenteritis, let the baby’s stomach rest for 15 to 20 minutes after vomiting or a bout of diarrhoea, then offer small amounts of liquid. Let the baby nurse if being breast-fed. If you are bottle-feeding, offer a small amount of an oral rehydration solution or regular formula.

Anti-diarrhoeal medications, such as Imodium, can be taken to slow the diarrhoea. In most cases, however, it is better for the body to clear itself of the virus or bacteria causing the gastroenteritis.

Use of antibiotics is also usually avoided because they are not effective against viruses, and their overuse contributes to the development of antibiotic-resistant strains of bacteria. 

Conclusion

Acute Gastroenteritis, which causes nausea, vomiting, abdominal cramping, fevers and diarrhea, is a common reason why patients come to us for medical care. In fact, gastroenteritis affects more than 600 million people around the world every year. 

The main focus of treatment is to prevent dehydration by drinking plenty of fluids. In severe cases, hospitalization and intravenous fluids are necessary.