Vomiting and diarrhea can happen for a number of reasons.
A stomach virus or bacterial gastrointestinal (GI) infection is the most likely cause in children, but these infections can also affect adults.
A number of other reasons exist for these symptoms, such as drinking too much alcohol. Often, vomiting and diarrhea occur together with fever, but not always.
Here are the most common causes of simultaneous vomiting and diarrhea symptoms, with and without fever:
Viral gastroenteritisViral gastroenteritis is an intestinal infection and it’s often referred to as the stomach flu. It is, however, unrelated to influenza (the flu) since it is caused by different viruses.
Common causes of gastroenteritis include:
norovirusrotirusadenovirusastrovirusWhile all of these viruses can affect people of any age, the latter three are most common in infants and toddlers.
These viruses are transmitted from person to person by contact with infected stool and vomit. This can happen when a person with the infection doesn’t wash their hands thoroughly after using the restroom and then touches objects or prepares food for others.
In addition to vomiting and watery diarrhea, symptoms of viral gastroenteritis include:
abdominal pain and crampingnauseafever, on occasionFood poisoningFood poisoning is an infection of the GI tract often caused by bacteria, parasites, or viruses.
You can get food poisoning by eating contaminated food. This can happen at home or in restaurants when food is handled incorrectly or not cooked properly.
Several bacteria can cause food poisoning, including:
E. coliCampylobacterListeria monocytogenesSalmonellaShigellaStaphylococcus aureusSymptoms of food poisoning can start within hours of eating and often resolve within a few hours or days. Unless symptoms are severe, this usually happens without medical treatment.
Vomiting and watery diarrhea are the most common symptoms of food poisoning. Other symptoms include:
abdominal pain and crampingnauseafeverbloody diarrheaTreler’s diarrheaTreler’s diarrhea is a digestive tract disorder that’s most often caused by viruses, parasites, or bacteria in water or food. It’s most likely to occur when you’re visiting an area with a different climate or sanitation practices than what you’re accustomed to at home.
Treler’s diarrhea generally clears up within a week. Watery diarrhea and cramps are the most common symptoms, but treler’s diarrhea can also cause:
nauseafeverflatulence (gas)bloatingtenesmus, or the urgent need to he a bowel movementYou can check the Centers for Disease Control and Prevention (CDC) website to see if there is a health notice for the regions to which you recently treled.
Stress or anxietyGastrointestinal function may be influenced by the stress response. In fact, stress and anxiety commonly cause a number of gastrointestinal symptoms, including:
nauseaconstipationindigestionheartburnStress hormones slow motility, or movement, in the stomach and small intestine. They also trigger an increase in motility in the large intestine, leading to some of these symptoms.
Stress and anxiety he also been linked to the development and worsening of symptoms of irritable bowel syndrome (IBS) as well as inflammatory bowel disease (IBD).
PregnancyThe body goes through numerous changes during pregnancy. Morning sickness is the most common cause of vomiting in pregnancy. Despite its name, morning sickness can occur at any time of the day.
Some people develop hyperemesis gridarum, a condition that causes severe nausea and vomiting during pregnancy.
Vomiting and diarrhea in pregnancy can also be caused by hormonal changes, new food sensitivities, and dietary changes. Prenatal vitamins also cause diarrhea in some people.
Gastroenteritis, common during pregnancy, may also cause these symptoms.
Overeating or overdrinkingOverindulging in food or drink can cause vomiting and diarrhea at the same time along with:
upset stomachheartburnbelchinga feeling of uncomfortable fullnessThe type of food you eat also matters. Eating large amounts of greasy or sugary foods may irritate your stomach and cause vomiting and diarrhea at the same time within hours.
Overeating is even more likely to cause these symptoms if you already he a gastrointestinal condition, such as IBS, stomach ulcers, acid reflux, or gastroesophageal reflux disease (GERD).
The relationship between alcohol and the gut is complex. Some types of alcohol, including sugary alcoholic drinks, can cause diarrhea by inducing a quicker gut transit time. This decreases digestion, as the gut doesn’t he time to absorb the nutrients or other substances that are rapidly passing through it.
High alcohol use can cause a condition known as alcoholic gastritis, which is an irritation of the stomach lining. Acute gastritis can occur after drinking high amounts of alcohol quickly, or gastritis can become chronic in people who drink alcohol regularly.
Gastritis may cause symptoms like:
upper abdominal pain or burningnauseabloatingregurgitationSymptoms may improve or worsen after eating, depending on the food you eat.
MedicationsVomiting and diarrhea are potential side effects of many medications. This may be related to the way the medication works or because it contains additives that irritate the stomach.
Your age, overall health, and other medications you take can also increase the chance of side effects.
Medications that commonly cause vomiting and diarrhea at the same time include:
antibioticsnonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin) and aspirinchemotherapy drugsmetformin (Fortamet, Glumetza)One way antibiotics can cause vomiting and diarrhea is by killing the “good” bacteria that live in your GI tract. This allows bacteria called Clostridioides difficile to become overgrown, which can result in symptoms similar to severe food poisoning.
Taking medication with food can sometimes relieve symptoms. You can speak with a doctor about the best way to take your medication and reduce the chance of side effects.