Dysentery: Types, Causes, Symptoms, Treatment, & Prevention

What is Dysentery?

Dysentery is an infection and inflammation of the intestines that results in bloody or mucusy diarrhea. Additional symptoms that may occur include nausea, stomach pains, fever, and vomiting.

Dysentery is a condition that may be caused by a bacterial or parasite infection. Typically, these illnesses spread as a consequence of inadequate sanitation or hygiene.

The majority of instances of dysentery are mild. But, some individuals may develop severe symptoms and complications of dysentery.

Dysentery is a term that refers to bloody diarrhea that may sometimes involve mucus. It may be caused by infectious bacteria, parasites, or irritation of the intestines due to chemicals.

When it comes to dysentery infections, the most prevalent is bacillary dysentery (also known as shigellosis) (1). This shigellosis is caused by bacteria known as shigella.

Amebic dysentery, often known as amebiasis, is another common type of dysentery. Amebiasis is caused by Entamoeba, a single-celled parasite.

In the United States, the majority of persons who suffer dysentery show only mild symptoms that subside within just a few days. However, this is a reportable illness, which means that a person who has it should notify the authorities. This helps in the prevention of dysentery outbreaks.

In this article, I will explain to you the types, causes, symptoms, treatment, and complications of dysentery. Additionally, you will also get valuable information about the diagnosis of dysentery as well as its prevention.

What are The Types of Dysentery?

So as we have discussed above, there are 2 types of dysentery.

1) Bacillary Dysentery (Shigellosis)

It is caused by shigella bacteria and is the most common type of dysentery.

2) Amebic Dysentery (Amebiasis)

It is caused by an amoeba (single-celled parasite) called Entamoeba histolytica and is mainly found in tropical areas.

What are The Symptoms of Dysentery?

Symptoms of dysentery differ depending on whether the infection is bacterial or parasitic.

a) Bacillary Dysentery Symptoms

Bacillary dysentery symptoms generally begin one to two days after infection and these symptoms can last up to 7 days, according to the Centers for Disease Control and Prevention (CDC) (2).

Symptoms may include the following:

  • Diarrhea, which may contain blood
  • Fever of 100.4°F (38°C) or higher
  • A sense of need to evacuate feces even though the intestines are empty
  • Abdominal cramps or pain

Typically, symptoms linger between 5 and 7 days. Though, some individuals may have symptoms for four weeks or longer (3). In a few cases, a person’s bowel habits may take many months to recover.

Antibiotics may significantly reduce the length of sickness and may even prevent the infection from spreading to others. But, antibiotics are normally used only when symptoms are severe.

b) Amebic Dysentery Symptoms              

A person suffering from amebic dysentery may face the symptoms mentioned below (4):

  • Abdominal pain and cramps
  • Diarrheal fluids that may include blood, mucus, or pus
  • Fatigue
  • Intermittent constipation
  • Fever with chills

A physician may give medicines to eliminate the parasitic infection.

What are The Causes of Dysentery?

There are two distinct types of dysentery, each having its own set of reasons. These are discussed in further detail below.

1) Cause of Shigellosis or Bacillary Dysentery

Bacillary dysentery is caused by the bacterium Shigella. These shigella bacteria may be contracted in the methods mentioned below (5):

  • Consuming shigella contaminated food.               
  • When a person does not wash their hands properly using the bathroom,
  • When a person touches a surface contaminated with shigella bacteria and then touches his/her nose, mouth, and eyes
  • Sexual interaction with a person who is undergoing treatment for bacillary dysentery
  • Swallowing water from a lake or river while swimming

Shigella bacteria may persist in a person’s feces for one to two weeks after they have recovered from illness symptoms (5). Every person in the family should continue to maintain rigorous cleanliness to avoid the spread of infection to others.

Shigella can spread in social as well as communal groupings, such as daycare centers.

2) Cause of Amebiasis or Amebic Dysentery

Entamoeba histolytica is the parasite that causes amebic dysentery.

In the majority of instances, amebic dysentery occurs when humans consume water or food that is contaminated through stools having Entamoeba eggs (6).

The following individuals are often at risk of acquiring acute amebic dysentery:

  • Pregnant women
  • Persons taking corticosteroids
  • Newborn children
  • Malnourished persons
  • Persons suffering from cancer

Similar Symptomatic Conditions

Certain illnesses may show symptoms that are similar to dysentery. Several examples include the following:

1) Infection with Escherichia Coli

It is a type of bacterial infection. Typically, it is transmitted to humans by consumption of contaminated foods, such as undercooked or raw ground meat products, raw milk, and contaminated raw vegetables and sprouts with feces (7). Symptoms may include the following:

  • Diarrhea, perhaps with blood 
  • Abdominal cramp
  • Fever
  • Vomiting

2) Usage of Antibiotic

Antibiotic use may cause Clostridiodes difficile (bacteria) overgrowth, and this may lead to pseudomembranous colitis (inflammation of the large intestine).

Among the various symptoms of pseudomembranous colitis some of them are (8):

  • Abdominal spasms
  • Fever
  • Diarrhea

3) Hookworm Infection

It is a parasitic disease that may result in bloody diarrhea. This infection is more prevalent in areas with warm, humid weather and inadequate sanitation (9). Its primary mode of spread is via contact with contaminated soil when walking barefoot.

Persons with a minor illness may have no symptoms. In most cases, itching as well as a localized rash are the initial indicators of infection. Severe infections may cause the following symptoms:

  • Diarrhea
  • Abdominal pain               
  • Loss of appetite
  • Weight reduction
  • Fatigue
  • Anemia

How is Dysentery Diagnosed?

A person who is facing acute dysentery symptoms should contact a physician for proper diagnosis and suitable treatment.

To diagnose dysentery, a physician may:

  • Perform a physical examination (tenderness may be present in the lower abdomen)
  • Inquire about the individual’s symptoms and when these symptoms began;
  • Enquire if the person has returned from a foreign trip.

Diarrhea can be caused by many conditions. If you are not having other symptoms of dysentery, your doctor will suggest diagnostic testing to decide which bacteria are present. This comprises a blood test and a lab test of a stool sample.

If a person has returned from a trip, they may be required to give one or even more stool samples. And if there is a doubt of amebic dysentery but the stool sample of the patient is negative for the parasite, then the patient may require a colonoscopy to check the mucosal surface of the intestines.

A patient with a suspected liver abscess may need hepatic fluid aspiration to assist in diagnosing the abscess (6).

If a patient’s symptoms persist, their doctor may suggest gastrointestinal diagnostic imaging, such as an ultrasound scan or an endoscopy.

What is the Treatment of Dysentery?

Laboratory studies will determine if dysentery is caused by Shigella, Entamoeba, or some other pathogen (10). Your physician will consider this information before prescribing your treatment.

Normally, an individual experiencing diarrhea or vomiting should consume lots of water to avoid dehydration. Severe dehydration may need intravenous fluid replenishment (11).

Treatment of Bacillary Dysentery

Because dysentery normally resolves on its own within 3–7 days, thus most patients do not need treatment. If the individual is suffering from diarrhea, then he/she should consume enough water to prevent dehydration. Anti-diarrheal medications should be avoided if the stool is bloody.

Over-the-counter (OTC) medication, like bismuth subsalicylate (Pepto-Bismol), can aid relieve belly cramps and diarrhea. Over-the-counter pain relievers, such as acetaminophen can be taken to relieve painful cramps.

You should avoid OTC diarrhea medicine that slows down the intestines, like loperamide or atropine-diphenoxylate, which can make dysentery worse.

If diarrhea or other symptoms are acute, then the physician may recommend antibiotics. But sometimes the bacteria that cause it are often resistant. So, if your doctor recommends an antibiotic and you don’t get improved after a couple of days, then your strain of Shigella bacteria might be resistant, and your doctor may need to modify your treatment plan.

Treatment of Amebic Dysentery

Individuals suffering from amebic dysentery may get medicine to treat the parasitic illness (6).

In case you have amoebic dysentery with symptoms, you may take medicine to eliminate the parasites in your blood, liver, and intestines. You may need to stay on these medications for about 10 days.

Medicines for Amebic Dysentery

People who have amebic dysentery are given metronidazole or tinidazole or ornidazole. These medicines are capable of eliminating parasites. In certain cases, a follow-up medication is used to ensure that all parasites have been eradicated.

In rare situations, amebic dysentery may cause complications like intestinal issues or liver abscesses. Such cases may need surgery.

What are the Complications of Dysentery?

A person may face some serious medical complications. These are particularly prevalent in those with weakened immune systems.

Some of the dysentery-related complications are as follows:

1) Dehydration

Frequent diarrhea and vomiting may often cause dehydration. This may soon become life-threatening in newborns and small children.

2) Bloodstream Infections

People with weak immune systems, like HIV or cancer patients, may develop these infections.

3) Liver Abscess

Amebic dysentery may result in a liver abscess (12).

4) Postinfectious Arthritis (PIA)

Postinfectious arthritis occurs in around 2% of patients who contract a specific strain of the Shigella bacterium called S. flexneri. These individuals may have joint pain, painful urination, and eye irritation. PIA might last for months or even years.

5) Hemolytic Uremic Syndrome (HUS)

It is a disorder in which the small blood vessels of the kidneys become inflamed and damaged. It is a rather uncommon complication of Shigella infection, caused by S. dysenteriae.

Anyone who feels they are getting dysentery-related complications should immediately seek medical assistance.

Prevention of Dysentery

Dysentery outbreaks are often caused by poor sanitation or hygiene. To avoid illness, individuals should routinely wash their hands with soap and water, particularly after using the toilet and before preparing meals.

Individuals going to places with warm, humid climates and poor hygiene are at a greater risk of acquiring dysentery.

While visiting such locations, a person should take the following precautions:

  • Consume only that water that is from a trustworthy source, such as bottled water.
  • Before drinking, check that the water bottles’ seal is unbroken
  • Use only bottled or filtered water while cleaning your teeth;
  • Avoid peeled fruit or vegetables, unless you peel them yourself
  • Don’t use ice cubes, since the water source may be contaminated
  • Eat thoroughly cooked food.
  • Avoid food and beverages sold by street vendors

When someone close to you suffers from dysentery, then:

  • Use hand sanitizer or wash your hands often with soap and water
  • Always wash your hands before you cook or eat food.
  • Don’t share cups, towels, or other personal items with the person having dysentery.


Dysentery may occur as a result of poor hygiene habits or travel to places with poor sanitation. Mild symptoms of dysentery usually disappear on their own without medical help.

However, those who acquire serious symptoms must consult a physician. Treatment is required to avoid any possible complications of dysentery.


Dysentery is an infection as well as inflammation of the intestines that results in bloody or mucusy diarrhea. Nausea, abdominal pain, fever, and vomiting are its other potential symptoms. This condition may be caused by bacterial or parasite infection.

Outbreaks of dysentery are more prevalent in areas with warm, humid climates and poor sanitation. Dysentery may be prevented by taking the proper precautions while going to high-risk places and by good hygiene practices.

In the United States, most instances of dysentery are mild and don’t need any treatment, so they don’t need to be taken care of. Individuals who encounter severe symptoms, on the other hand, should consult a physician for a diagnosis as well as suitable therapy. This minimizes the possibility of complications.





2) Shigella


3) Shigella Symptoms


4) Amebiasis


5) Shigella – Sources of Infection and Risk Factors


6) Amebiasis


7) E. coli


8) Pseudomembranous Colitis


9) Hookworm FAQs


10) Amebiasis – General Information


11) Diarrhoea and Vomiting Caused by Gastroenteritis: Diagnosis, Assessment and Management in Children Younger than 5 Years.


12) Amebic Liver Abscess



Disclaimer: This article is intended for informational purposes only. Any information associated with this article should not be considered as a substitute for prescriptions suggested by local health care professionals.


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