Most adults will experience diarrhoea — loose watery stools — at some time. Most people do not need any specific treatment for infectious diarrhoea as it usually improves on its own in a couple of days. However, it is important to drink plenty of liquids to keep well hydrated. This is especially important for children and babies.
The treatment for non-infectious diarrhoea will depend on the cause.
Treating and preventing dehydration
Suitable fluids to drink when you have diarrhoea include oral rehydration fluids, water, clear soups and broths and diluted juices. If you have nausea, try taking small sips of fluid often.
Dehydration may be treated with oral fluids or, if severe, with intravenous fluids (i.e. into a vein, via a drip).
Oral rehydration fluids
Oral rehydration is the first line therapy for diarrhoea. Rehydration fluids contain not only the water replacement that is required in diarrhoea or vomiting-induced dehydration, but also important electrolytes that must be replaced. If dehydration is sufficiently severe, water alone is inadequate.
Oral rehydration products replace fluids lost, but do not treat the cause. However, many causes of diarrhoea are self-limiting and don’t need specific treatment.
Available products include Gastrolyte, Hydralyte, Pedialyte and Repalyte. These should be mixed exactly to the manufacturer’s directions. It is very important to comply with the expiry dates of the rehydration solutions once they have been opened or made up.
Other suitable fluids include:
diluted cordial (one part cordial concentrate to 20 parts water); and
diluted soft drink or juice (one part juice or soft drink to 5 parts water).
While you have diarrhoea, avoid caffeine (tea, coffee, cola drinks), alcohol and foods that are fatty, very sweet or high in fibre. Dairy products may aggravate symptoms, but yoghurt (which contains less lactose than milk) may be tolerated.
Resume eating solid food slowly and choose foods that are bland, low in fat and low in fibre. This includes crackers, boiled potatoes, plain rice, or toast.
Anti-motility medicines (sometimes called anti-diarrhoeal medicines) can help slow down the diarrhoea. These medicines may be useful in relieving symptoms of mild or moderate diarrhoea if short term control is needed, for example during travel. These medicines can be obtained from pharmacies.
Anti-motility medicines should not be used if you have severe or bloody diarrhoea and may be dangerous in this instance. They should never be used to treat diarrhoea in infants and children.
Available products include:
loperamide (e.g. Gastro-Stop, Imodium, Stop-It); and
diphenoxylate and atropine (e.g. Lomotil, Lofenoxal).
These medicines may worsen bacteria-induced diarrhoea, and may cause drowsiness. Alcohol should be avoided.
Antibiotics are prescribed only in some cases of diarrhoea that is caused by bacteria or parasites. Your doctor may request a stool sample to test for bacteria or parasites before starting antibiotic treatment.
If you’ve had an episode of gastroenteritis, you may benefit from taking probiotics.
When to see your doctor
If your diarrhoea has not improved with self-care measures, you may need further treatment.
See your doctor if:
you have diarrhoea that contains blood or mucus;
you have a fever;
you have symptoms of dehydration (thirst, lack of energy, passing less urine than normal, dizziness or the skin on the back of your hand being slow to return to position after being pinched upwards);
you have abdominal pain; or
diarrhoea lasts for more than 5 days.
Diarrhoea and your medicines
Diarrhoea can affect the way that some medicines (such as the contraceptive pill) are absorbed. If you take the contraceptive pill and develop diarrhoea, you should use a back-up method of contraception, such as condoms, until your next menstrual period because the diarrhoea may make the pill less effective.
If you are taking any other regular medicine, talk to your doctor about the effects that diarrhoea may have had on its effectiveness.
Some types of diarrhoea can very easily be passed on. It is important that children do not go to school or childcare when they have diarrhoea.
Likewise do not prepare food for people if you are suffering from diarrhoea. You may go on being infectious for a time after you feel better, so keep strict food hygiene precautions for a week after any diarrhoeal illness.
Wash your hands thoroughly with warm water and soap after going to the toilet and before food preparation — teach your children to do the same. Hand sanitisers are useful when you are not near a sink.
There is a vaccine available that can prevent gastroenteritis (or reduce the risk of severe gastroenteritis) caused by rotavirus infection. Rotavirus vaccine is given as part of the routine childhood immunisation schedule in 2 or 3 doses.