Dysentery: Symptoms, Causes & Treatment

Dysentery is an intestinal infection that leads to diarrhea containing blood, mucus, or pus. It often causes additional symptoms such as abdominal pain, cramping, fever, nausea, and vomiting, and can result in dehydration.

It is most often caused by bacteria or parasites transmitted through the fecal-oral route. Infection can occur after consuming food or water contaminated with feces, due to poor hand hygiene, or while living in or traveling to places with poor sanitation conditions.

Regardless of the cause, it’s important to see a gastroenterologist, primary care provider, or pediatrician as soon as symptoms appear. Getting evaluated and treated early can help prevent complications such as dehydration.

Main symptoms

The main symptoms of dysentery are:

• Diarrhea with blood, mucus, or pus

• High fever above 100.4°F (38°C) that starts suddenly

• Urgent need to have a bowel movement

• Nausea and vomiting, which may contain blood

• Abdominal pain or cramping

• Extreme fatigue (tiredness)

• Headache

• Loss of appetite

With dysentery, bowel movements become more frequent and vomiting may occur. These symptoms can lead to significant fluid loss and increase the risk of serious dehydration.

For this reason, it’s important to see a gastroenterologist, pediatrician, or primary care provider as soon as possible at the first signs of dysentery. You should also drink at least 2 liters of water daily and use oral rehydration solutions to prevent dehydration.

Treatment should begin as soon as possible to help prevent complications beyond dehydration, such as intestinal bleeding and malnutrition.

Diarrhea vs dysentery

Both diarrhea and dysentery can cause more frequent bowel movements and changes in stool consistency. However, dysentery is marked by the presence of blood or mucus in the stool, which is not typical of uncomplicated diarrhea.

Confirming a diagnosis

Dysentery is diagnosed by a gastroenterologist, primary care provider, or, in children, a pediatrician. Diagnosis is based on the person’s symptoms, medical history, and recent travel, and stool tests may be ordered to confirm the cause.

To confirm the diagnosis and determine the organism responsible for dysentery, the provider may request a stool ova and parasite test to check for parasite eggs or cysts. If bacterial dysentery is suspected, a stool culture followed by antibiotic susceptibility testing may also be performed.

In a stool culture, the sample is processed in the lab to identify the bacteria present. Additional testing is then performed to determine which antibiotics the bacteria may respond to and whether they show any resistance.

Possible causes

Dysentery is caused by bacteria or parasites spread through the fecal-oral route. These organisms affect the gastrointestinal (GI) tract and irritate the intestinal lining, leading to symptoms.

These bacteria and parasites are mainly spread through:

• Eating contaminated food

• Drinking contaminated water or other beverages

• Not washing your hands before and after using the bathroom, or after changing the diaper of a baby with dysentery

• Swimming in contaminated water, such as pools or lakes

• Living in or traveling to areas without adequate sanitation

• Sexual activity, particularly anal contact

Although infections are the most common cause of dysentery, the condition can also occur after long-term use of certain medications that damage the intestinal lining. In such cases, it’s important to consult a healthcare provider, who may recommend stopping or switching the medication.

Different types

Dysentery can be divided into two types based on the type of infection:

1. Bacterial dysentery

Bacterial dysentery is the most common type. It can be caused by bacteria such as Shigella, Salmonella, Campylobacter, or Escherichia coli (E. coli).

When dysentery is caused by Shigella, it may also be called bacillary dysentery or shigellosis. According to the CDC, symptoms usually begin about 1 to 2 days after infection and often last about 5 to 7 days.

2. Amebic dysentery

Amebic dysentery is caused by the protozoan Entamoeba histolytica. This parasite can also contaminate food and water and may cause diarrhea when the parasite burden is high.

This type of dysentery is also called amebiasis. Symptoms usually appear 2 to 5 weeks after infection with the protozoan.

Treatment options

Treatment for dysentery should begin as soon as the condition is diagnosed. Ideally, treatment should start at the first signs of symptoms to help prevent complications such as dehydration, malnutrition, liver abscess, or toxic megacolon.

A provider may recommend oral hydration with fluids such as water, juice, tea, and coconut water, along with oral rehydration solutions. In cases of severe dehydration, treatment is given in the hospital with fluids and electrolytes delivered directly into a vein.

Your diet should include light, easy-to-digest foods and plenty of fluids, such as cooked vegetables, vegetable soup, gelatin, and fruit.

In cases of bacterial dysentery, the doctor may prescribe antibiotics to treat the bacteria. In cases of amebic dysentery, antiparasitic or other anti-infective prescription treatment may be used, depending on the organism identified.