Gastroenteritis is inflammation that spreads from your stomach into your intestines, causing pain, vomiting and diarrhea. When it feels like it’s “coming out both ends,” you’ve usually ingested a virus, bacteria or chemical by mistake. Most of the time, it goes away by itself.
Gastroenteritis means inflammation in your stomach and intestine. Inflammation makes these organs feel swollen and sore. It causes symptoms of illness, like nausea, vomiting, abdominal pain and diarrhea.
Gastroenteritis often happens when you get an infection in your gastrointestinal (GI) tract. Bacteria and viruses can cause food poisoning and stomach flu infections. Chemicals can also cause gastroenteritis.
Infectious gastroenteritis is the most common type. It’s caused by an infection in your gastrointestinal tract (your stomach and/or intestines). Viruses, bacteria, fungi or parasites may cause the infection.
Chemical gastroenteritis can happen if you ingest toxic chemicals, which can contaminate food and water sources. You can also get it from heavy doses of alcohol or drugs, including some medications.
Just about everyone gets gastroenteritis, likely more than once. Most of the time, it’s not serious. But in more vulnerable populations, it can be. Around the world, gastroenteritis is a leading cause of death.
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Symptoms involving your intestines (diarrhea, cramps), together with symptoms involving your stomach (nausea, vomiting) are the hallmarks of gastroenteritis. You’ll know it if it’s “coming out both ends.”
Gastroenteritis symptoms may include:
Gastroenteritis symptoms often come on suddenly. Gastrointestinal symptoms appear first. You might have diarrhea, stomach pain or cramps, nausea and/or vomiting many times in a short period.
As the day goes on, you may or may not begin to experience what are called “systemic symptoms” — symptoms that affect the rest of your body. These may include fever, chills and body aches.
The most common types of gastroenteritis only last a day or two. Your body can overcome most bacterial and viral infections on its own. Some types may last longer or need treatment to go away.
Gastroenteritis happens when your immune system activates to defend your stomach and intestines from harm. It sends inflammatory cells to help fight infections and repair injured tissues.
This is usually a temporary (acute) response to a temporary threat or injury. It takes a short time to work, and then, the inflammation goes away. Longer-lasting (persistent) gastroenteritis is unusual.
Infectious diseases or toxic chemicals can trigger acute gastroenteritis.
Infectious gastroenteritis is caused by an infection in your gastrointestinal tract, like a:
Infections are the most common cause of acute gastroenteritis.
Viral infections cause viral gastroenteritis, which is the most common type overall. Viruses cause 60% of all gastroenteritis cases. Norovirus alone accounts for 50% of all viral gastroenteritis cases.
Viral gastroenteritis sometimes goes by the nickname, “stomach flu,” although this isn’t a medical term. Influenza (flu) viruses don’t cause viral gastroenteritis. Viruses that can cause “stomach flu” include:
Bacterial infections cause bacterial gastroenteritis. Common bacterial gastrointestinal infections include:
Parasite infections cause parasitic gastroenteritis. Common parasite infections include:
Fungal infections can cause fungal gastroenteritis. The most common fungal infections are:
Chemicals can injure and inflame the lining of your stomach and intestines. Some chemicals do this even in small amounts. Others, like alcohol and certain medications, can cause gastroenteritis in larger doses.
Causes of chemical gastroenteritis include:
Infectious gastroenteritis is contagious. When you have an infection in your gastrointestinal system, it infects your poop. Infections can spread from your poop to anyone who comes into contact with it.
Microscopic traces of poop can linger on bathroom surfaces, diaper changing areas and people’s hands if they don’t wash well. These traces can transfer to others who touch them, or to their food or water.
Chemical gastroenteritis isn’t contagious. But it can affect many people in one place at one time. If you get toxic poisoning from food, water or your environment, others sharing those things may also get it.
The most common way to get a gastrointestinal infection is from contaminated food or water. You can also catch it by touching an infected person, or by touching a surface that an infected person touched.
Gastrointestinal infections are most contagious during the period when you have symptoms, and for two days after. These last two days are when your body is shedding the infection through your poop.
Just about everyone gets gastroenteritis. But you’re more likely to get it more frequently if you:
Most of the time, gastroenteritis is brief and ends by itself. When this is the case, the primary complication to look out for is dehydration. This is more of a risk for children and senior citizens.
When you’re having frequent diarrhea or vomiting, you’re losing a lot of fluids and electrolytes. If you can't replace them fast enough, you could become dehydrated and develop electrolyte imbalances.
If gastroenteritis lasts a long time, it could begin to damage your stomach and intestines. For example, you might develop ulcers in your organs that bleed. Only a few types of gastroenteritis can last longer.
Some specific causes of gastroenteritis can have their own side effects. These are separate from the effects of gastroenteritis itself. Certain infections or toxins can do more lasting damage to your body.
People with weakened immune systems and people with less access to clean water, nutrition, sanitation and healthcare are more vulnerable to gastroenteritis. They might get it more often, and for longer.
Children in less developed countries and senior citizens in long-term care facilities are more at risk of serious complications from gastroenteritis. This is because their health status is lower to begin with.
Healthcare providers can usually recognize gastroenteritis by your symptoms. They’ll ask you when your symptoms started and what was going on at the time that could have triggered them.
If you have unusual symptoms, or if they want to investigate your symptoms further, they may order some tests. A poop test or blood test can help prove gastroenteritis and rule out other conditions.
In most cases, gastroenteritis goes away by itself. The best way to help your body recover is to give it lots of rest and fluids. You might want to stick with bland, easy-to-digest foods for a few days.
But certain, less common causes of gastroenteritis do need treatment. If your symptoms don’t seem to be going away, or you believe you have a type of toxic poisoning, tell a healthcare provider.
Most of the time, medical treatment for gastroenteritis is supportive. That means the treatment supports your body’s natural healing process rather than curing gastroenteritis. It might include:
But some causes of acute gastroenteritis may need medication to go away. For example, you may need a specific antibiotic or antiparasitic medication to treat a specific type of bacterial or parasite infection.
If you have chemical gastroenteritis due to toxic poisoning, you may need additional treatment to help clear the toxin out of your body. The treatment will depend on the toxin and on your condition.
You should feel better within two to three days after your symptoms first started, or after you started medication if you needed it. If you aren't feeling better yet, let your healthcare provider know.
Not every case of gastroenteritis is preventable. But there’s a lot we can do to reduce our personal risk and prevent common gastrointestinal infections from spreading in our communities. For example:
For most people, gastroenteritis isn’t serious. But for people with weaker immune systems, it can be. This includes children under 5, adults over 65 and anyone with a lower health status in general.
If you know that you or someone in your care has a weaker immune system, take special care to avoid dehydration and exhaustion from gastroenteritis. Seek healthcare if symptoms don’t improve soon.
You may not have much appetite with gastroenteritis, and that’s natural. Your irritated stomach and intestines won’t be able to digest or absorb many of the foods that you would normally eat anyway.
It’s OK to eat a very limited diet for a few days until the inflammation goes down. Just focus on bland foods that are easy to digest and avoid foods that might make your gastrointestinal symptoms worse.
Contact a healthcare provider if you notice any unusual or red flag symptoms, such as:
Gastritis is inflammation in your stomach.
Gastroenteritis is inflammation in your stomach and intestine. (Enteritis means inflammation in your small intestine, but it may spread to your large intestine, too.)
Gastritis causes stomach symptoms, like stomach pain, nausea and vomiting. Inflammation in your intestines affects your poop, causing diarrhea.
Gastroenteritis means that you have both.
Gastroenteritis is a universal experience, but that doesn’t make it easy to go through. If your time has come to weather the storm, take care, and know that it will most likely be over in a day or two.
It can be alarming to have sudden and frequent symptoms like diarrhea and vomiting. It can feel like something is really wrong. But those symptoms mean that your body is already taking care of it.
Most people won’t need or benefit from medications. Many infections have no antidote. But a few do, and a few might need meds to go away. If your gastroenteritis isn’t going away, tell a healthcare provider.
If you’re immunocompromised or caring for someone with a weaker immune system, don’t hesitate to stay in touch with a healthcare provider during gastroenteritis, and let them know how it’s going.
Last reviewed by a Cleveland Clinic medical professional on 09/25/2023.
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