Dysentery is a type of infection that can cause very severe diarrhoea. It’s usually passed on through poor hygiene. There are two main types: bacillary dysentery, which is more common, and amoebic dysentery.

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.

The shigella organism enters the body through the mouth and then multiplies in the bowel, which produces a range of symptoms.

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
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.
• Fever.
• Feeling down or depressed.

Amoebic dysentery may not show any symptoms for months or even years. However, a person that is infected will pass cysts in their stools when they go to the toilet and subsequently infect their surroundings if hygiene standards are poor.

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.