What Is Dysentery?

Dysentery is severe diarrhea that’s characterized by visible blood in the stool. It’s caused by bacteria and must be treated with an antibiotic. 

Although dysentery was more common historically, people still get dysentery today. In the United States, about half a million people get dysentery each year. There about 8,000 diarrhea-related deaths annually, although not all of those are caused by dysentery.

Here’s what you should know about the signs of dysentery, and when to get medical attention. 

What Is Dysentery?

Dysentery is severe diarrhea that is caused by infection. The infection in the intestines causes diarrhea and occasionally vomiting, and can lead to dehydration because people with the condition lose so much fluid. 

Dysentery Symptoms and Types

There are two types of dysentery, both caused by micro-organisms. The most common in the United States, and around the world is bacillary dysentery. This type, caused by the bacteria from the family Shigella, is also known as shigellosis. Shigella symptoms generally begin 1-2 days after coming into contact with the bacteria, then last for a week. They include:

• Diarrhea that may or may not be bloody
• Fever
• Stomach pain

Amebic dysentery is the second form of the condition. It’s rare in the United States and more common in tropical areas of developing countries, where sanitation is challenging. Amebic dysentery is caused by contact with a certain protozoa, a single-celled parasite. In this case, the protozoa is E. histolytica. 

Here’s where things get a bit confusing. Not all people who come into contact with E. histolytica will develop dysentery. Only 10-20% of people who come into contact with the parasite will get sick at all, and most will develop a less severe condition known as amebiasis. However, some people will develop dysentery, characterized by diarrhea and bloody stool. 

The symptoms of amebiasis appear 2-4 weeks or more after exposure to the parasite. They include: 

• Diarrhea
• Stomach cramping and pain
• Fever (in the case of amebic dysentery)

Causes

Dysentery is most common in warm climates and in places where it’s difficult to follow proper sanitation guidelines, including handwashing. The condition is most common in people who live in or travel to these areas, including central and south America and Africa. 

In the United States, dysentery is also most common along people who don’t have access to proper sanitation, most importantly clean water. People who lack resources like proper plumbing or who live in institutions like nursing homes with fewer resources can be at increased risk for dysentery in the United States.

Dysentery in the developed world, including the United States, is also most common in men who have sex with men, including gay and bisexual men. Both forms of dysentery can pass through anal and oral-anal sex, which could explain why outbreaks in developed countries have been linked to men who have sex with men.

People who have a compromised immune system—including those on immunosuppressive medications, or are undergoing chemotherapy or have HIV—are at increased risk of contracting dysentery. 

How Dysentery Is Spread

People who contract dysentery do so by coming into contact with the bacteria Shigella or the protozoa E. histolytica. This can happen when a person swallows water that contains these microorganisms or puts their fingers in their mouth after coming into contact with these microorganisms.

Person-to-person transmission of dysentery is also common. This happens when a person’s mouth comes into contact with particles of poop from a person who is already infected with dysentery. This is easier than it may sound. If someone with the condition doesn’t wash their hands properly, they may have fecal matter on their fingers. Anything they touch, like food or a cup, can then become infected.

Because dysentery can be spread through contact with fecal matter, the condition can also be spread through anal and oral-anal sex.

Diagnosis and Treatment

The treatment for dysentery will depend on what type you contract. Your doctor will ask you about your symptoms and recent travel, if any. They will usually send a stool sample to the lab to determine whether you have dysentery and what type.

Shigella can resolve on its own. People with shigella can use over-the-counter treatments like Pepto Bismol, but shouldn’t use medication, like Imodium, that can interfere with digestion. It’s important to get plenty of rest and hydration while you have shigella.

In some cases, shigella will be treated with an antibiotic. Unfortunately, some strains of the bacteria are resistant to antibiotics, so your doctor will have to determine whether this is an option for you.

Amebiasis often requires treatment with antibiotics, even if you don’t develop symptoms. You might need two different types of antibiotics.

Prevention

There are two schools of thought for preventing dysentery. The first to be aware of is reducing risk for contracting the disease in the first place. This is particularly important for people who are traveling to areas that have a higher rate of dysentery. 

To reduce your risk for contracting dysentery while traveling to tropical, developing countries, you must be aware of what you’re eating and drinking. The CDC has the following recommendations:

• Drink only sealed beverages or water that has been boiled for one minute
• Avoid unsealed beverages, including ice cubes
• Don’t eat fresh fruit or vegetables unless you have washed and peeled them yourself
• Avoid unpasteurized milk or dairy
• Skip the food from street vendors, who may not have access to proper sanitation equipment

In order to prevent the person-to-person transmission of dysentery when someone has been diagnosed with the condition, take the following precautions:

• Frequently wash hands, especially after using the bathroom and before cooking
• Avoid all sex, including oral, vaginal and anal, until diarrhea has stopped for at least one week
• Avoid swimming until diarrhea has been resolved for at least one week

A Word From Verywell

Dysentery is an uncomfortable and scary condition. However, most people in the United States are at a very low risk for contracting dysentery. By taking proper precautions, including hand washing, you can further reduce your risk of contracting the condition or having serious complications. If you’re worried that you may be suffering from dysentery, contact your doctor for diagnosis and treatment.