Patient information from BMJ

Amebic dysentery

Last published:Apr 08, 2025

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

What is amoebiasis?

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

Amebiasis 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 ameba.

• 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 amebiasis?

The main symptom of amebiasis is diarrhea. This means you get loose, watery stools and you need to go to the bathroom more often than usual. 

You may also get:

• diarrhea with blood or mucus in it (also known as amebic dysentery)

• bleeding from your rectum

• pain in your abdomen

• pain when going to the bathroom to pass stools

• fever.

You may also lose your appetite and lose weight.

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

If you’ve been traveling recently and then became ill with diarrhea, 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 amebas. You might also have a blood test.

If your doctor thinks you’re severely dehydrated, you might have to go to the 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 amebiasis?

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

You'll need a prescription from a doctor for these medications. They can come as pills, 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 medication to fully clear the infection from your intestines. You usually need to take this for 5-10 days.

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

• Nausea, vomiting, or diarrhea

• Pain in your abdomen

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

• Weakness or dizziness 

• Dark-colored urine 

• Pain while urinating 

• Loss of appetite 

• Rash

• Trouble sleeping 

• Blurred vision or headaches.

What happens next?

Most people who get treatment for amebiasis 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 diarrhea improves. This is because without treatment, the amebas 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 amebas have spread to your liver, you may need more tests and treatment.

Sometimes the amebas 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 diarrhea 

• 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 amebiasis, 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 amebiasis, you can still get infected again. To prevent another infection, make sure you wash your hands after going to the bathroom and before handling food.