Patient information from BMJ

Amoebic dysentery

Last published:Apr 08, 2025

Amoebiasis is an infection in your intestines (bowels) caused by a type of parasite called an amoeba. It’s spread through contaminated food and water, and contact with infected people. If left untreated, it can cause severe diarrhoea and other complications. 

What is amoebiasis?

Amoebiasis is a bowel infection caused by a parasite called an amoeba. It leads to very bad diarrhoea, and can cause serious illness and even death if left untreated.

Amoebiasis is more common in countries with poor sanitation and limited access to clean water.

The infection spreads through contaminated food, water, and person-to-person contact. You can catch it by:

• Eating or drinking something contaminated with the amoeba.

• Touching something that has traces of an infected person’s stool (like their hand) and then touching your mouth, such as when eating.

• Living in crowded conditions where hygiene is harder to maintain.

• Having a weakened immune system (for example, due to chemotherapy or HIV).

• Having oral or anal sex.

What are the symptoms of amoebiasis?

The main symptom of amoebiasis is diarrhoea. This means you get loose, watery stools and you need to go to the toilet more often than usual. 

You may also get:

• diarrhoea with blood or mucus in it (also known as amoebic dysentery)

• bleeding from your rectum

• pain in your abdomen

• pain when going to the toilet to pass stools

• fever.

You may also lose your appetite and lose weight.

Diarrhoea can cause your body to lose too much water (dehydration), so be sure to drink plenty of water. If you have severe diarrhoea that doesn’t go away after a few days, it’s important to see your doctor.

If you’ve been travelling recently and then became ill with diarrhoea, you should tell your doctor where you went. This will help them decide the right treatment.

Your doctor will examine your abdomen to check for signs of swelling. They might also take a sample of your stool so it can be tested for amoebas. You might also have a blood test.

If your doctor thinks you’re severely dehydrated, you might have to go to hospital. There, you might be given drinks called rehydration solutions. People who are so ill that they can’t drink liquids can be given fluids by intravenous (IV) drip.

What are the treatment options for amoebiasis?

The treatment for amoebiasis is antibiotics. Antibiotics are usually used to kill germs called bacteria but they also kill amoebas.

You'll need a prescription from a doctor for these medicines. They can come as tablets, and you’ll usually need to take them for 3-10 days, depending on which one you are given.

After finishing the antibiotics, you may need another medicine to fully clear the infection from your intestines. You usually need to take this for 5-10 days.

Medicines for amoebiasis can cause side effects in some people, but they are usually mild. They include:

• Nausea, vomiting, or diarrhoea

• Pain in your abdomen

• A bitter or metallic taste in your mouth or a tongue that looks coated (furry) 

• Weakness or dizziness 

• Dark-coloured urine 

• Pain while urinating 

• Loss of appetite 

• Rash

• Trouble sleeping 

• Blurred vision or headaches.

What happens next?

Most people who get treatment for amoebiasis will recover and the infection will go away. If you don’t get treatment, you could become very sick or the infection could become life-threatening. You could also pass the infection to others, even if the diarrhoea improves. This is because without treatment, the amoebas are still in your body.

In rare cases, the infection can break through the wall of your bowels and affect other parts of your body, such as your liver. If your doctor thinks the amoebas have spread to your liver, you may need more tests and treatment.

Sometimes the amoebas can cause a more serious condition called fulminant colitis. Fulminant colitis is rare but it causes severe inflammation (swelling) of the bowel, and it can be life-threatening. The symptoms include: 

• Pain all over your abdomen 

• Very bad diarrhoea 

• Fever.

It's important that you see a doctor as soon as possible if you get any of these symptoms.

If you’re getting treatment for amoebiasis, your doctor may give you advice on how to avoid spreading the infection to those around you. If you work with food, or if you're a healthcare worker, you should stay off work until your doctor says it's safe for you to return.

Even if you recover from amoebiasis, you can still get infected again. To prevent another infection, make sure you wash your hands after going to the toilet and before handling food.