Causes of travellers' diarrhoea

The most common cause is a bacteria - either E. coli or campylobacter. However, it can also be caused by other bacteria, viruses, protozoa, parasites and toxins (bad chemicals) from foods.

When you are travelling and eating food and drink which may have been prepared in less hygienic conditions, your food and drink may easily have been contaminated and so give you diarrhoea. It is also easy to pick up these bugs on your hands and then get infected.

How long does travellers' diarrhoea last?

Most occurrences happen within the first week of travel. It usually only lasts 1-7 days during which time a small proportion of people can be stuck in bed. In a few people (5%) symptoms can last two weeks or longer. In rarer cases (about 1.5%) travellers' diarrhoea can lead to serious illness and even long-term bowel problems.

How can I treat travellers' diarrhoea?

Most travellers' diarrhoea will cause a relatively mild illness and it may not require any treatment beyond fluid replacement and a light diet - small amounts of foods such as rice or bananas which can be digested easily.

• Drink plenty of water - it is important to keep well hydrated as you will be losing a lot of fluid. Either use sachets of rehydration salts or take a rehydration spoon and make your own rehydration drink with salt, sugar, and clean (boiled/filtered) drinking water. Try and drink 3-4 litres (6 pints) of fluid per day. Avoid alcohol as this can cause further dehydration.
• If you have a long journey with limited toilet stops, or an important meeting then loperamide can usually reduce the frequency of diarrhoea. It reduces spasm in the bowel and also helps with cramps. It works best if started early in the diarrhoea. Loperamide should not be used if there is high fever or severe abdominal pains, or for longer than 2 days. It should not be taken by children under age 12.
• Taking an antibiotic can significantly reduce the severity and duration of travellers' diarrhoea, but only if the diarrhoea is caused by bacteria - see causes of diarrhoea. Dr Fox prescribes azithromycin to take with you as a 'stand-by' medication. Ciprofloxacin is no longer recommended as an antibiotic for travellers' diarrhoea due to increased antibiotic resistance and rare severe side effects.
• If there is significant associated vomiting (uncommon) then Avomine, which is prescribed for travel sickness, could also be taken to help to reduce fluid loss. Avomine cannot be used if also taking azithromycin antibiotic.

Take treatment with you

A short course of the antibiotic azithromycin alone or together with the anti-diarrhoeal loperamide is an effective treatment for travellers' diarrhoea. Dr Fox supplies both medications as a stand-by treatment to take with you to be prepared if you do contract travellers' diarrhoea.

Azithromycin

Travellers most likely to benefit from antibiotics for travellers' diarrhoea:

• If going to a remote location with little or no access to good medical assistance.
• If you are at high risk of the diarrhoea leading to severe illness, e.g. poorly controlled diabetes, renal impairment, heart failure, reduced CD4 HIV or other reduced immunity.
• With pre-existing bowel problems where infection may trigger a relapse, e.g. ulcerative colitis, Crohn's disease, coeliac disease, and previous bowel surgery.
• With a tendency to severe travellers' diarrhoea (on the basis of previous travel experience).

Note: azithromycin is not licensed to treat travellers' diarrhoea, but it has been prescribed by doctors as an 'off-label' treatment for many years. If a medicine is used for an off-label (unlicensed) purpose the manufacturer is not liable in case of adverse events. Doctors take the responsibility for the prescribing.

Cautions

If you have known allergy to azithromycin, erythromycin, or clarithromycin you should not take azithromycin for travellers' diarrhoea.

There are some medical conditions where you should not take azithromycin:

• A tendency to irregular heartbeat or other heart disease.
• Myasthenia gravis.
• Liver disease.
• Kidney disease.

It is not recommended to take azithromycin when trying to conceive, or during pregnancy and breastfeeding, without first discussing with your own GP.

There is a very rare theoretical risk of abnormal heart rhythm if azithromycin is taken at the same time as some other medications - please check this list.

Dosage

Treatment with azithromycin is 500mg once a day for 3 days. Start the course as soon as you get diarrhoea, not before. It is not a preventative.

Side effects

If there are any side effects the most common are stomach upset, nausea, and diarrhoea. For further details read the azithromycin patient information leaflet supplied with the tablets.

Antibiotic guardianship

To combat antibiotic resistance please:

• Only use antibiotics when needed
• Never share antibiotics
• Always complete course as instructed
• Take unused medicine to local pharmacy for disposal

Loperamide (Imodium)

Loperamide reduces the spasm in the bowel and reduces the frequency of diarrhoea. It works best if started early in the diarrhoea. Loperamide (Imodium) is available from pharmacies over the counter.

Cautions

Loperamide should not be taken:

• When diarrhoea starts after a course of antibiotic.
• Where there has been prolonged constipation before diarrhoea starts.
• Where the diarrhoea contains blood and there is a high fever.
• Not suitable for children.
• Best avoided in pregnancy and breastfeeding women.

Dosage

Take two loperamide 2mg capsules straight away. Then take one capsule after each episode of diarrhoea for up to 5 days. The maximum number of capsules in a day is 8 (16mg). The usual amount is 3-4 capsules (6-8mg) daily.

Side effects

There may be no side effects. Possible side effects include feeling tired, dry mouth, feeling drowsy, dizzy, and sick. Rashes are possible. For further details read the loperamide patient information leaflet supplied with the tablets.

Travellers' diarrhoea - when to seek medical help

Seek medical help if:

• There is blood and green or yellow slime in the diarrhoea.
• Diarrhoea does not begin to improve within 24–36 hours despite self-treatment.
• Persistent high fever (over 38.5°C for 48 hours) especially if in a malaria zone.
• Severe abdominal pains.
• Associated rash.
• It is difficult to take enough fluids and the person is showing symptoms of dehydration (increased risk in infants and children): restless or irritable, very thirsty, sunken eyes, and dry wrinkly skin. A saline drip may be needed to restore hydration levels.

Increased risk of travellers' diarrhoea

• High risk destination - countries with less access to good hygiene conditions, including South and South East Asia, Central America, East, West and North Africa, South America.
• Under 30 years (especially backpackers, teenagers and children).
• Previous severe travellers' diarrhoea.
• Chronic disease or weakened immune system.
• Visiting friends and family after having lived abroad for some time.
• Travelling in the hot and wet seasons.
• Reduced stomach acid - surgically or due to medication such as omeprazole.
• Eating from street vendors and markets.
• Cruise ships can also be associated with outbreaks.

Avoiding infections

• Avoid street food or eating at places that appear dirty.
• Drink only bottled (with intact seal) or clean (boiled/filtered/treated) drinks (see water purification).
• Do not use local tap water to clean teeth.
• Try to eat only freshly prepared food that is thoroughly cooked and served very hot.
• Avoid ice in drinks, ice cream, shellfish, salads, and cold foods in buffets which can be contaminated.
• Avoid unpasteurized milk and cheese.
• Fruit that you can peel yourself is safe.
• Frequent hand washing - using soap and water is better than hand gel, but often less practical.
• Travel vaccines - all people who are travelling should be up-to-date with the recommended vaccines for your destination(s) - see the NHS Fit for Travel website.