Grumblin’ Tums: Traveller’s Diarrhoea

Written by: Dr Geoff Lewis

Thailand and South East Asia is one of the most popular places for those travelling and backpacking on a gap year. One of the delights of travelling around this area is the food and drink. It’s out of this world. But it can also send you out of this world too.

You may find yourself in a small roadside café where the food’s cheap, but beware. Less than 24 hours later, you may be unwell with watery diarrhoea, stomach-ache, nausea and a fever.

Dr Geoff Lewis looks at travellers’ diarrhoea, one of the most common illnesses on the road, and specifically how to tackle it…

What has happened?

They’ve picked up traveller’s diarrhoea. They’ve most likely picked it up from a bacteria called E-coli. There are a few others bacterias such as Salmonella, Shigella, and Campylobacter, and between them they account for most cases of traveller’s diarrhoea. Sometimes it can be caused by viruses, and occasionally by a parasite called Giardia. Very often when faeces are examined no bug is found at all. If the symptoms had started very quickly with more nausea and vomiting they may have developed food poisoning from a bacterial toxin or chemicals in the food.

What will happen next?

Most cases of traveller’s diarrhoea will get better by themselves over several days, but 10% will still have symptoms a week later, and some may even have symptoms a month later. If the symptoms develop over a week later, then last more than 10 days, they may have caught the parasite Giardia, which needs to be identified and treated.

Traveller's diarrhoea

How could they have avoided catching traveller’s diarrhoea? 

The key to this is safe food and water. Knowing what to do can prevent traveller’s diarrhoea. Food should be properly cooked, avoiding high risk foods such as market stall food, cold sauces, raw or undercooked meat, or seafood. Drinks should be bottled; watch the staff open the bottle and avoid ice cubes and ice cream.

Some restaurants have been known to buy bottling machines. There is little you can do about this level of subterfuge except try to use reputable cafes and restaurants.

There is some evidence from medical trials that Probiotics may reduce the incidence of traveller’s diarrhoea.

How should they treat traveller’s diarrhoea?

Most cases of travellers’ diarrhoea improve spontaneously with good fluid replacement. You can buy sachets of oral rehydration salts, a solution of salts and sugars which can be freely used while the diarrhoea lasts. In the absence of these sachets, especially in more isolated places, a mixture can be made up as follows:

  • 1 litre of clean water
  • Half a teaspoon of salt
  • 6 level teaspoons of sugar

Loperamide is an antidiarrhoeal medicine which can be started straight away and and used as instructed on the packet until the diarrhoea settles.

If they have a high fever or blood in the stools many trials have shown that a short course of high dose antibiotics can help reduce the duration of the traveller’s diarrhoea. The most commonly used are Ciprofloxacin or Azithromycin.

Most situations allow the graded use of rehydration, followed by Loperamide, then rarely the use of antibiotics. Some situations such as expeditions may need quicker action, when the early use of both Loperamide and a high single dose of Antibiotic may be appropriate.

Squat toilets are a nightmare if you have traveller's diarrhoea

What if the traveller’s diarrhoea continues? 

If they remain unwell or produce more symptoms then they need to be evaluated by a doctor who can send a stool sample off and tailor the treatment to the bug found.

Shouldn’t we be avoiding unnecessary antibiotic use?

Yes, most cases only need plenty of rehydration as explained above, with Loperamide until the diarrhoea settles. The problem with overuse of antibiotics is that many countries allow ‘over the counter’ antibiotic sales which has produced a lot of resistance in the commoner bugs such as E Coli. Salmonella, Shigella and Campylobacter.

Many countries use repeated courses of drugs such as Ciprofloxacin in the elderly, children, and the immunocompromised in hospitals, which can encourage a bacteria called C. Difficile to overgrow, which is difficult to treat. Short and occasional high dose courses of this antibiotic in the well traveller are much less likely to do this.

And finally?

As long as the traveller takes reasonable care with fluids and food, making sure they buy from reputable clean sources, they should be fine and enjoy a healthy holiday and avoid traveller’s diarrhoea. All fluids and food being prepared by the traveller should be fresh and well cooked with good hand and utensil hygiene. It makes sense to carry a basic medical pack with you to cover these medical problems especially if you are likely to be isolated and away from medical care.

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