Dysentery

Dysentery is an infection of the intestines that causes diarrhoea containing blood or mucus.

Other symptoms of dysentery can include:

• painful stomach cramps
• nausea or vomiting
• a fever of 38C (100.4F) or above

Dysentery is highly infectious and can be passed on if you don't take the right precautions, such as properly and regularly washing your hands.

Types of dysentery

There are two main types of dysentery:

• bacillary dysentery or shigellosis – caused by shigella bacteria; this is the most common type of dysentery in the UK
• amoebic dysentery or amoebiasis – caused by an amoeba (single-celled parasite) called Entamoeba histolytica, which is mainly found in tropical areas; this type of dysentery is usually picked up abroad

Treating dysentery

As dysentery usually clears up on its own after three to seven days, treatment isn't usually needed.

However, it's important to drink plenty of fluids and use oral rehydration solutions (ORS) if necessary to avoid dehydration.

Over-the-counter painkillers, such as paracetamol, can help relieve pain and a fever. Avoid antidiarrhoeal medications, such as loperamide, because they can make things worse.

You should stay at home until at least 48 hours after the last episode of diarrhoea to reduce the risk of passing the infection on to others.

How you can avoid passing on dysentery

Handwashing is the most important way to stop the spread of infection. You're infectious to other people while you're ill and have symptoms.

Take the following steps to avoid passing the illness on to others:

• Wash your hands thoroughly with soap and water after going to the toilet. Read more about how to wash your hands.
• Stay away from work or school until you've been completely free from any symptoms for at least 48 hours.
• Help young children to wash their hands properly.
• Don't prepare food for others until you've been symptom free for at least 48 hours.
• Don't go swimming until you've been symptom free for at least 48 hours.
• Where possible, stay away from other people until your symptoms have stopped.
• Wash all dirty clothes, bedding and towels on the hottest possible cycle of the washing machine.
• Clean toilet seats and toilet bowls, and flush handles, taps and sinks with detergent and hot water after use, followed by a household disinfectant.
• Avoid sexual contact until you've been symptom free for at least 48 hours.

As shigella is easily passed on to others, you may need to submit stool (poo) samples to be given the all clear to return to work, school, nursery or a childminder.

The type of shigella you have and whether or not you or others are in a risk group will influence how long you need to stay away. 

Risk groups are people in certain occupations – including healthcare workers and people who handle food – as well as people who need help with personal hygiene and very young children. Your environmental health officer will be able to advise you about this.

When to see your GP

It's not always necessary to see your GP if you have dysentery because it tends to clear up within a week or so.

However, you should see your GP if your symptoms are severe or they don't start to improve after a few days. Let them know if you've been abroad recently.

If your symptoms are severe or persistent, your GP may prescribe a short course of antibiotics. If you have very severe dysentery, you may need treatment in hospital for a few days.

Reducing your risk of catching dysentery 

You can reduce your risk of getting dysentery by:

• washing your hands with soap and warm water after using the toilet and regularly throughout the day
• washing your hands before handling, eating or cooking food
• avoiding sharing towels
• washing the laundry of an infected person on the hottest setting possible

Read more about food safety and home hygiene.

If you're travelling to a country where there's a high risk of getting dysentery, the advice below can help prevent infection:

• Don't drink the local water unless you're sure it's clean (sterile) – drink bottled water or drinks in sealed cans or bottles.
• If the water isn't sterile, boil it for several minutes or use chemical disinfectant or a reliable filter.
• Don't clean your teeth with tap water.
• Don't have ice in your drinks because it may be made from unclean water.
• Avoid fresh fruit or vegetables that can't be peeled before eating.
• Avoid food and drink sold by street vendors, except drinks in properly sealed cans or bottles.

Read more about food and water safety abroad.

What causes dysentery?

Bacillary and amoebic dysentery are both highly infectious and can be passed on if the faeces (poo) of an infected person gets into another person's mouth.

This can happen if someone with the infection doesn't wash their hands after going to the toilet and then touches food, surfaces or another person.

In the UK, the infection usually affects groups of people in close contact, such as in families, schools and nurseries.

There's also a chance of picking up the infection through anal or anal-oral sex ("rimming").

In developing countries with poor sanitation, infected faeces may contaminate the water supply or food, particularly cold uncooked food.