When you have a stomach ache with vomiting and diarrhea, it can be hard to know for sure what’s causing your illness. It could be food poisoning or stomach flu, also known as viral gastroenteritis.

In rare cases, you could also be experiencing dysentery. It may sound like a disease from long ago, but dysentery is actually still around — there are about half a million cases in the United States per year.

Dysentery is an intestinal infection that causes severe diarrhea with blood or sometimes mucus present in the stool.

Here, we’ll talk about both gastroenteritis and dysentery and whether they’re the same thing.

Dysentery is a form of gastroenteritis. You can think of gastroenteritis as the umbrella term while dysentery is more specific.

Some of the other types of gastroenteritis include:

What is gastroenteritis?

Viral gastroenteritis is also inflammation or irritation of the intestines caused by a virus. However, 15%–20% of gastroenteritis cases are caused by bacteria. Some cases may also be parasitic.

Bacterial gastroenteritis presents with similar symptoms, including stomach cramping and watery diarrhea, but it’s caused by bacteria (or even food poisoning) rather than a virus.

What is dysentery?

Dysentery is basically severe gastroenteritis. The term is used to describe cases of gastroenteritis that has severe, frequent, watery, or bloody diarrhea as one of its symptoms.

The causes are the same, but symptoms may vary.

Dysentery can be caused by poor hygiene or by coming into contact with water, food, or anything that has been contaminated with fecal matter.

There’s also bacterial dysentery, which is caused by contact with certain bacteria including Shigella, Campylobacter, Salmonella, or enterohemorrhagic E. coli.

Amebic dysentery is a type caused by a parasite that infects the intestines. This parasite is found in the feces of those with the infection.

Key takeaway

There are many types of gastroenteritis, but dysentery is one of the more serious ones. Most types of these diseases are caused by exposure to a pathogen by either poor hygiene or eating contaminated food.

Dysentery is treated the same as gastroenteritis: fluid rehydration, symptom control, and treatment for whatever the exact cause may be.

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The signs of gastroenteritis will vary slightly depending on what type you have. Symptoms may include:

A stool test can detect rotavirus or norovirus, but there aren’t tests for other viruses that cause gastroenteritis.

Most stool studies that your healthcare professional will order will test for specific types of bacteria and parasites so specific treatment can be started if necessary.

Dysentery may have similar symptoms to gastroenteritis except that they’re more intense and frequent. Symptoms include:

Most notably, dysentery usually causes blood in the stool and sometimes mucus, which can look fatty. Most cases of gastroenteritis usually do not include bloody diarrhea.

It’s very important to seek medical attention any time there’s a fever or severe bloody or watery diarrhea, even before signs of dehydration begin.

See a doctor if your diarrhea does not improve within 2 days and especially if you’re experiencing signs of dehydration, like:

Usually, dysentery will clear on its own in 3 to 7 days, but it’s important to stay hydrated and to see a doctor if you’re not feeling better.

For gastroenteritis, see a doctor immediately if:

  • you can’t keep down liquid
  • you’re vomiting blood
  • you’re feeling dizzy or weak

Viral gastroenteritis should also clear on its own, and typically antibiotics will not be given unless a bacterial source is identified.

Dysentery is a severe form of gastroenteritis. Gastroenteritis is the term used to describe any diarrheal condition caused by an infection. Dysentery is used to describe severe cases of gastroenteritis that include frequent watery and/or bloody diarrhea.

Whether it be dysentery or milder forms of gastroenteritis, it’s important to see a doctor if you can’t keep liquid down, you’re dizzy or weak, or symptoms last longer than 3 or 4 days.