Medically Reviewed by Minesh Khatri, MD on November 14, 2022
4 min read

Dysentery is an infection in your intestines that causes bloody diarrhea. It can be caused by a parasite or bacteria.


What type you have depends on what caused your infection.

Bacillary dysentery is the most common type of dysentery. It results from bacteria called Shigella. The disease is called shigellosis. About 500,000 people in the U.S. get it every year.

Amoebic dysentery comes from a parasite called Entamoeba histolytica. You're more likely to get this kind of dysentery if you travel to a tropical location that doesn’t have good sanitation.

You can get dysentery if you eat food that's been prepared by someone who has it. For example, you might get it if the person who made your food is sick and didn't properly wash their hands. Or you can get dysentery if you touch something that has the parasite or bacteria on it, such as a toilet handle or sink knob. 

Swimming in contaminated water, such as lakes or pools, is another way you might catch dysentery.

You can sometimes carry the bug that causes dysentery for weeks or years without knowing it. You can still pass the infection to other people, even if you don't have symptoms.


Symptoms can show up 1-3 days after you get infected. In some people, the symptoms take longer to appear. Others never get symptoms.

Each type of dysentery has slightly different symptoms.

Bacillary dysentery causes symptoms like:

Amoebic dysentery usually doesn't cause symptoms. If you do feel sick, you'll notice problems 2-4 weeks after you're infected, such as:

  • Nausea

  • Diarrhea

  • Belly cramps

  • Weight loss

  • Fever

Rarely, amoebic dysentery leads to more serious problems like liver abscess, which is a collection of pus in the liver. Symptoms include:

  • Nausea and vomiting

  • Fever

  • Pain in the upper right part of the belly

  • Weight loss

  • Swollen liver

Call your doctor if diarrhea, cramps, and other symptoms are severe, or if they don't get better within a week. Let your doctor know if you recently traveled to a country where dysentery is common.

Dysentery symptoms look like a lot of other intestinal illnesses, including a common stomach virus. A lab technician will need to look at a sample of your stool under a microscope to see if you have dysentery, and if so, what type.


Bacillary dysentery treatment

 Most people with bacillary dysentery don't need prescription medicine. The infection usually passes on its own within a week.

While you wait for it to clear, you can do a few things to help you feel better. Drink plenty of water or "rehydration" drinks, like sports drinks, or electrolytes to bring back the fluid you lost through diarrhea.

Medicine with bismuth subsalicylate (Pepto-Bismol) may ease symptoms like belly cramps and diarrhea. You can also take an over-the-counter pain reliever like acetaminophen to manage painful cramps.

Don't take an over-the-counter diarrhea medicine like loperamide (Imodium) unless your doctor recommends it. These medications can make dysentery worse.

If the infection doesn't clear up on its own in a few days you may need treatment with antibiotics. Talk to your doctor.

Amoebic dysentery treatment

 If you have amoebic dysentery with symptoms, you can take medicine to kill the parasites in your blood, intestines, and liver. You'll stay on these medications for about 10 days. Doctors treat amoebic dysentery that doesn't cause symptoms with drugs such as iodoquinol or diloxanide furoate.

Dysentery safety

Dysentery is very contagious. Stay home from work or school until you've been diarrhea-free for at least 48 hours to avoid passing the infection to others. Wash your hands often and don't prepare food for anyone else for at least 2 days after your symptoms clear up. Also avoid sex until you feel better.

Once the infection is gone, clean your house well to kill the germs. Wash your sheets, towels, and clothes in hot water. Disinfect toilet seats, flush handles, sink handles, doorknobs, and other places you often touch.

If you visit a tropical or less developed country where dysentery spreads, follow these tips:

  • Drink and brush your teeth with bottled or canned water only, not tap water.

  • Order your drinks without ice.

  • Only eat raw fruits and vegetables that have a peel.

  • Cook any produce that you can't peel.

  • Don't eat food from street vendors.

When someone close to you has dysentery:

  • Wash your hands often with soap and warm water or use hand sanitizer.

  • Don't share towels, cups, or other personal items with the person who has dysentery.

  • Wash your hands before you cook or eat.

The most common complication of dysentery, or any type of diarrhea, is dehydration. It’s important to drink plenty of fluids if you or your child have diarrhea. 

Other complications of dysentery are related to dehydration and may include: 

  • Severely low potassium levels, which can cause life-threatening heartbeat changes

  • Seizures

  • Haemolytic uraemic syndrome (a type of kidney damage)

Additional dysentery complications are: 

  • Toxic megacolon

  • Rectal prolapse