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
There are two main types of dysentery:
Bacillary dysentery or shigellosis – caused by shigella bacteria; this is the most common type of dysentery
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.
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.
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.
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.
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.