A brief introduction to gastroenteritis

How do I pronounce gastroenteritis?


For the sake of easy reading in this article, we will refer to gastroenteritis as gastro. Gastro is often referred to as the ‘stomach flu’ due to its symptoms commonly being diarrhoea and vomiting. What is interesting is that it is actually not a type flu at all. What happens with gastro, is that your stomach and intestines become inflamed which is typically caused by a parasitic, viral or bacterial infection.

Most people can recover without treatment, but it is also important to know when you need to seek medical advice.

As informative as this article may be, it is written only to serve as a guideline and is not intended to act as a diagnosis or treatment for any associated condition. We would suggest that you please consult with your doctor or healthcare professional for that.


What are the common causes of gastro?

There are a variety of ways that gastro is spread, it is most commonly spread through:

  • Not washing your hands after going to the toilet or after changing a diaper.
  • Eating or drinking contaminated food or water, such as sewage-contaminated water.
  • Coming into contact with someone who has the virus (viral infection).
  • Eating raw or unhygienically prepared food.

Parasitic Gastroenteritis

This is the least common cause of gastro. However, it is possible to pick up organisms like cryptosporidium or giardia by drinking contaminated water or by swimming in a contaminated swimming pool.

Viral Gastroenteritis

The most common cause of gastro, is a viral infection. It can be caused by different strands of viruses, but the most common two are the rotavirus and the norovirus. It is highly contagious and precautions should always be taken so as to lower your risk of infection.

Causes of viral gastro

People with the highest risk of infection are:

  • Infants and young children under five years old.
  • Elderly people, particularly those living in nursing homes.
  • Children and adults who suffer from weak immune systems.
  • People in group situations such as schools, hospitals, nursing homes and even cruise ships.

Diagram of gastro


This is the most common cause of diarrhoea in small children and infants. Children act as the ‘spreading agent’ who then infect other adults and children. The virus enters the patient from their mouth, being spread orally.

Your symptoms will start to show after two days from infection, and can be any or all of the following:


  • Vomiting
  • Loss of appetite
  • Watery stool
  • Diarrhoea
  • Nausea


This strand of virus can affect people of all ages and is especially contagious. It is known to spread through contaminated water, food, surfaces and infected people. This type of virus is commonly found in crowded areas, as mentioned above. It can also lead to severe diarrhoea.

Other symptoms can include:


It is important that you lower your chances of infection by ensuring your food is always hygienically prepared, that you do not eat undercooked food or drink contaminated water and always wash your hands after changing a diaper or going to the toilet.

How long will my viral gastro last?

The majority of people will only display symptoms for two to three days, and after which, they tend to make a full recovery and have no long-lasting side effects. However, the symptoms can last up to 10 days, after which, it is recommended that you consult with your health care professional. If your symptoms continue after two to three days and show no sign of improvement, it is a good idea to seek medical advice and attention.

Are there are complications for viral gastro?

When to call your doctor

The biggest complication for gastro is dehydration, this is obviously more severe in small children and babies. You will need to call your doctor if you or your child display any of the following symptoms:

  • Blood in stools or dark, close to black coloured stools
  • Feeling confused and lethargic
  • Nausea
  • Sunken eyes or fontanelle (these are the soft spots on your baby’s head) from dehydration
  • Not being able to produce tears when crying
  • Dry tongue and mouth
  • Feeling faint and dizzy
  • Not being able to urinate for over eight hours
  • Urine is a dark yellow or even brown
  • Continuous diarrhoea for over a few days

How will my doctor diagnose viral gastro?

Your doctor will typically diagnose you based on your symptoms, conducting a physical exam as well as if similar cases have appeared in your community.

A stool test can also be conducted, where you will need to give your doctor your stool for him/her to have examined – this will help to pick up if it is a rotavirus or norovirus.

What will be the treatment for viral gastro?

There is no specific treatment for viral gastro, your doctor will most likely recommend that you drink plenty of fluids and in severe cases, hospitalise you in order to get fluids into you via a drip (intravenously).

There are possible rehydrate solutions available at your local pharmacies too, speak to your doctor about these. Remember, antibiotics have no effect of viral gastro and should not be taken.

Are there home remedies for viral gastro?

The most important goal for your body is to stop it from becoming dehydrated, the following can be done in order to ensure a quick recovery with no long-term side effects:

  • Constantly take small sips of water or suck on ice. Stay away from caffeinated drinks as these can dehydrate you further.
  • Don’t eat solids for a couple of days in order to let your stomach settle, rather opt for soups.
  • Try to stay away from spicy foods and opt for bland foods so as to help your stomach to get used to eating. Foods such as crackers, jelly, rice and chicken tend to help. Stay away from dairy products, cigarettes and alcohol.
  • Try and get plenty of rest to help your body to recover quickly.

The above list also applies to your children suffering from viral gastro.

Can I prevent viral Gastro?

The best way to avoid the spread of viral gastro is to try and stick to the following precautions:

  • Vaccinate your child against the rotavirus as this is most common in children.
  • Wash your hands and make sure your children wash their hands too. It is best to scrub them with soap for at least 20 seconds after going to the bathroom and before and after preparing food.
  • Avoid sharing eating utensils in your home and use separate towels in the bathroom.
  • Avoid close contact with people who have the virus.
  • Keep your surfaces in your home disinfected. Bleach with a litre of water works well as a disinfectant.
  • Take precautions when you travelling, such as avoiding tap water - ice cubes are also tap water! Also, avoid uncooked food. Raw fruits that have been peeled are also at risk for contamination.

Bacterial Gastroenteritis

A little bit about the difference between bacteria and a virus

Bacterial gastro occurs when bacteria has caused an infection in your gut. The difference between a virus and bacteria is simple. Both are airborne, however, a virus needs a living host to survive and multiply. When a virus enters your body, it will invade your cells and cause an immune response as it replicates itself inside the host. It does this by causing the cell it has taken over to make copies of the viral cell. It then destroys the host cell and takes over the body. Most viruses can be vaccinated against and people with a strong immune system can often fight off the virus without risking severe infection.

Bacteria are bigger than a virus. They exist in abundance in both living hosts, soil, water and plants, as well as other areas of the planet. They can be beneficial or harmful. For example, the bacteria in our gut helps us to digest and process food – this is a beneficial bacteria. Antibiotics help to cure the infection of harmful bacteria. The biggest difference between viruses and bacteria is that bacteria can cultivate on non-living surfaces. A virus on the other hand, changes the host cell’s genetic material to reproduce the virus itself.

Bacterial gastro

To get to the point, bacterial gastro causes an infection in your gut, which results in your stomach and intestines swelling and becoming inflamed. It is often the result of poor hygiene of consuming contaminated food or water.

Causes of bacterial gastro

There are a number of strands of bacteria that can lead to bacterial gastro, these being:

  • E. coli which are found in salads and often ground beef.
  • Bacteria found in pork called Yersinia.
  • Shigella which is often found in swimming pools and water.
  • Common bacteria found in meat, eggs and dairy products is known as Salmonella.
  • Staphylococcus is also found in dairy products, eggs and meat.
  • Campylobacter is found in meat and poultry.

When you are at risk:

  • You are at risk when a restaurant serves contaminated food to a number of people.
  • You are also at risk as bacterial gastro is easily spread from one person to another. This transferral happens through simply touching another person if that one person has it on their hands.
  • Another way of contamination is if you are infected and touch a surface, another person who touches the same surface is at risk of infection – it’s as easy as that to get infected and spread it! Bet you aren’t looking at public bathrooms in the same light anymore are you?

Symptoms of bacterial gastro

Your symptoms may vary depending on the bacteria causing your infection, as listed above. Your symptoms can include:

  • Feeling nauseous which leads to vomiting.
  • Suffering from watery stool and diarrhoea.
  • Having a fever over 39℃ (102.2℉).
  • Having blood in your stool.
  • Stomach cramps and pains in the abdominal area.
  • Suffering from a loss of appetite.

How long will my bacterial gastro last?

Bacterial gastro shouldn’t last more than five days in adults and two days in children.

Are there are complications for bacterial gastro?

When to call your doctor

If your symptoms do not improve after five days, you should call your doctor. If your infant is younger than three months old and is vomiting or has diarrhoea continuously for an extended period, then you will need to call your doctor. If you know you have a weak immune system, speak to your doctor about possible infection and prevention.

If you experience some more severe symptoms, listed below, then you will need to seek immediate medical assistance. However, this is not to say that every case of bacterial gastro will suffer from these, most patients have a swift recovery after a few days of infection with no long-term side effects.

Serious symptoms include:
  • High fever
  • No control over bowel movements
  • Muscle pain
  • Blood in the stool

How will my doctor diagnose bacterial gastro?

Your doctor will ask you questions about your symptoms and do a physical check – be prepared to answer these questions. He may also want to examine a sample of your stool if need be, this will help to determine the bacteria causing the infection.

A blood test may also be conducted to test for dehydration.

What will be the treatment for bacterial gastro?

Your doctor may prescribe antibiotics to kill off the bacterial infection. However, these are not often prescribed and are only used for the most severe cases. If you are at risk of severe dehydration, you may be hospitalised and connected to a drip to put fluid back into your system intravenously.

Often, your doctor will tell you to possibly take a few days off work to save you from potentially embarrassing runs to the toilet and most importantly, to not infect other people. Your doctor may also tell you to follow the list of home remedies below.

Are there home remedies for bacterial gastro?

  • Drink fluids throughout the day, try sucking on ice if you are feeling too nauseated to drink anything.
  • It is also possible to get over-the-counter rehydrate solutions, but it is always best to speak to your doctor about what products to use.
  • Drink liquids and eat foods with potassium, such as bananas. Potassium is a natural electrolyte which aids in normal muscle function and helps to balance the water in cells and body fluids.
  • Try and include foods with sodium – this helps to maintain blood pressure and hold water.
  • Ginger can help to aid in stomach cramps. Slice up some fresh ginger and put it in a cup with hot water, almost like a ginger tea.
  • Avoid dairy and high-fibre foods that could make your diarrhoea worse.

Can I prevent bacterial gastro?

Try and stick to a hygienic regime, if you have children, get them to follow one too:

  • Always wash your hands before and after handling food, as well as after going to the toilet.
  • If you are infected, don’t prepare food for other people.
  • Once your symptoms have stopped, don’t go to work for another 48 hours as you may still be infectious.
  • Use separate utensils and cutting boards for fruits and vegetables and raw meat (don’t mix raw vegetables with raw meat).
  • Always wash your vegetables before preparing a meal.
  • Try to avoid unpasteurised milk, raw shellfish such as oysters, and raw meat.
  • Keep your kitchen clean and sanitised.
  • Drink bottled water when travelling overseas or to other countries.

Disclaimer - is for informational purposes only. It is not intended to diagnose or treat any condition or illness or act as a substitute for professional medical advice.