Ten mistakes people make about gastro

By Dr Umberto Russo MBBS, FRACGP


Gastroenteritis, or ‘gastro’ as we commonly call it, is one of the top ten reasons our Doctors get called out after hours. While usually not life threatening, gastro can be a debilitating and unpleasant experience for patients and their carers, particularly when they don’t fully understand why they are suddenly sick.

Patients say to me “Doctor, I must have eaten something bad”, but truthfully food poisoning as a cause of gastro is only half the story. Here are the facts to help clear up ten common misunderstandings about gastro:

1. Gastro is not always caused by food poisoning

Gastro is an infection that has a number of causes. It can be caused by bacteria (such as salmonella), which is found in undercooked chicken or food left unrefrigerated for too long. However it is more commonly caused by viruses, such as rotavirus and norovirus (pictured). It can also be caused by parasites (such as Giardia) from contaminated water, or chemicals (toxins from poisonous mushrooms, for example).

2. Gastro is not just diarrhoea

Gastro is an inflammation of the digestive tract, so it affects both your stomach and intestines. Gastro can involve both diarrhoea and/or vomiting, and other symptoms as well. In fact gastro is sometimes called ‘stomach flu’ because it can also be characterised by nausea, fever and headaches.

3. Yes, gastro is contagious

Gastro viruses like norovirus and rotavirus, and parasites such as Cryptosporidium and Giardia are extremely contagious. The germs can be spread by the vomit or faeces of an infected person, through hand-to-hand contact (such as shaking hands) or by touching contaminated objects. Patients with norovirus, for example, remain contagious for up to two weeks after recovery. Hand washing, using soap and running water, is the best way to prevent the virus from spreading to other members of the family.

4. Gastro won’t always appear straight away

With some types of gastro you will feel sick immediately. But with some viruses it can take two or three days after exposure to the virus before the symptoms appear.

5. Gastro can be life-threatening

The main risk of gastro is dehydration, especially in babies, small children and the elderly. The vomiting and diarrhoea cause the body to lose a lot of fluid, so it is important to keep drinking adequate fluids. Offer the patient water, especially after a bout of vomiting or diarrhoea, even if it’s just a few sips at a time. Children may prefer to suck on ice cubes. 

If your baby is breastfed, continue to do this as often as baby will take it.

In the case of severe dehydration, patients will need to go to hospital for fluid replacement.

6. Gastro can be treated

For most healthy adults, symptoms of gastro should settle within a few days. But if you suspect you are dehydrated, or the patient in your care is dehydrated, you should contact a Doctor.

Treatment can include rehydration drinks (which contain a balance of water, salts and sugar) and medication for nausea, vomiting or fever. Antibiotics are only required in a small number of patients where the gastro is caused by a very small number of specific bugs such as Giardia. A sample of your diarrhoea may be tested for this.

7. You should try and eat if you have gastro

Most patients experience loss of appetite when they have gastro, and the conventional wisdom is that you shouldn’t eat. But doctors now advise that you should eat if you feel hungry. Eating helps the lining of the intestine to heal more quickly, and allows the body to regain strength. Start with small amounts of food like pasta, rice or dry biscuits or toast. And remember to keep up the fluids.

8. Gastro can take a few weeks or months to get over

Most gastro illnesses should pass within two or three days, but in some types of gastro, such as a giardia infection, symptoms can last for months if left untreated - and can recur. If you think you might have giardia, see your Doctor.

9. Gastro can be prevented

The best way to prevent gastro is prevent the spread of viruses and bacteria. Germs are transferred onto hands from the faeces of an infected person, which can often happen when changing nappies, for example. The germs from unwashed hands then end up on toys, doorknobs, kitchen surfaces, etc. Practise good hand hygiene, and teach your children from an early age the importance of washing hands with soap and water. Sick patients should stay away from childcare, preschool, school or work until there has been no vomiting or diarrhoea for at least 24 hours. Keep sick children away from swimming pools and communal toys, and wash down frequently touched surfaces in the house.

10. See your Doctor

For many patients, gastro will last a couple of days with some discomfort, and then you’ll feel back to normal. But gastro is not always straightforward. Sometimes the symptoms can drag on, or particularly vulnerable patients such as babies and the elderly can begin to deteriorate. If you are anxious about your own symptoms or someone in your care, it is best to seek a Doctor’s advice. If it is late at night or on the weekend, and your GP is closed, you can call 13SICK or use the 13SICK App to request an after hours doctor home visit. Our Doctors can advise the best treatment and get you started on medication if necessary.

Dr Umberto Russo MBBS (Adelaide), FRACGP is Chief Medical Officer at 13SICK, National Home Doctor Service. He has more than 25 years' experience both as a General Practitioner and a visiting home doctor, with a special interest in urgent medical care.

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