Bacillary dysentery is most common in the UK and is caused by a bacterium called Shigella, of which there are four species.
- Shigella sonnei (this is the most common cause of dysentery in the UK).
- Shigella flexneri.
- Shigella dysenteriae.
- Shigella boydii.
An amoeba (a parasite that uses our bodies to help it live) called entamoeba histolytica causes amoebic dysentery. They mainly live in tropical areas, so cases in the UK are very rare but it can be picked up abroad. They enter the body through contaminated food and drink and after moving through the digestive system they live in the intestine and can cause an infection. The amoeba can also exist as a cyst (a group of amoebae surrounded by a protective wall) and these are more likely to cause an infection as they can protect themselves much better from digestive acid in the stomach.
Most people in the UK who have dysentery only have mild symptoms and may not even visit a GP as the condition can settle within a few days. Severe infections are more common if you’re travelling abroad, and in some cases, dysentery can be fatal if not treated.
Symptoms of bacillary dysentery usually begin within one to three days of infection and can last from three to seven days.
The symptoms could include
- Watery diarrhea, sometimes containing blood, mucus or pus in severe cases.
- Feeling sick and vomiting.
- Abdominal pain.
- Feeling down or depressed.
Symptoms of amoebic dysentery are similar to bacillary dysentery, but there is more likely to be blood in the diarrhoea. This is because the amoebae attack the walls of the large intestine causing ulcers that can bleed. Ulcers can eventually result in loss of appetite and excessive weight loss. The passing of stools may also be painful.
Dysentery is spread from person to person through poor hygiene measures, for example not washing your hands after using the toilet. In the UK, most cases are spread through families and where people are in close contact, such as schools, nurseries, military bases and day–centres. The disease can be spread up to four weeks from infection into the body.
Dysentery is also spread through food that has come into contact with water contaminated with human sewage, such as in countries with poor sanitation systems. This is why more severe dysentery is more common in developing countries, where water supplies and sewage disposal are inadequate or where human faeces are used as a fertilizer.
If you have diarrhoea that contains blood or mucus you should see your GP. Tell them if you have been abroad.
Diagnosis is made by testing a stool sample to see if the bacteria that cause dysentery are present. Further investigations, such as an ultrasound may be used if dysentery has caused further problems such as an ulcer.
Dysentery is a notifiable disease: this means your GP is required to tell the local authority if you have it. It is important that the local authority knows, so that they can try to identify the cause and if necessary take measures to prevent the disease spreading to other people.
If you have diarrhoea and vomiting, it’s very important to drink plenty of fluids to replace those lost and stop you getting dehydrated. Water, fruit juice and isotonic (sports) drinks that replace salts and minerals are best. In severe cases, fluid can be given by intravenous drip at a hospital if required. If you have amoebic dysentery your GP may prescribe metronidazole.
Since most cases of dysentery are short, antibiotics are only used if the dysentery doesn’t clear up on its own. Antibiotics can also be used to stop the spread of dysentery to other people if there is a high risk.
The list below is a combination of the generic and brand names of medicines available in the UK. Each name provides a link to a separate website (Medicine Guides) where you can find detailed information about the medicine. The information is provided as part of an on–going medicine information project between NHS Direct, Datapharm Communications Ltd and other organisations.
The medicines listed below hold a UK licence to allow their use in the treatment of this condition. Unlicensed medicines are not included.
The list is continually reviewed and updated but it may not be complete as the project is still in progress and guides for new medicines may still be in development.
If you are taking one of these medicines for a different condition, or your medicine for this condition is not mentioned here at all, speak to your prescriber, GP or pharmacist, or contact NHS Direct on 0845 46 47.
Young children and babies who have dysentery can quickly become dehydrated. Its very important make sure they get plenty of fluids to replace those lost, or dysentery can be fatal.
Occasionally, amoebic dysentery can spread from the intestine through the bloodstream to other organs such as the liver, lungs and brain and can cause additional tissue damage. Surgery is usually needed if this happens.