Many conditions can cause diarrhea and vomiting, including intestinal infections and food poisoning. Less common causes may include bowel obstruction and pancreatic cancer.

According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), a person has diarrhea if they pass three or more loose or liquid stools per day.

In most cases, vomiting and diarrhea are temporary symptoms that improve without medical treatment. However, persistent vomiting or diarrhea can indicate an underlying condition.

In this article, we look at some common causes and treatments for vomiting and diarrhea. We will also discuss possible complications and when to see a doctor.

A woman experiencing vomiting and diarrhea sits on the toilet.Share on Pinterest
Common causes for vomiting and diarrhea include intestinal infections, food poisoning, and medication.

Gastroenteritis

Gastroenteritis is an intestinal infection that can occur due to viruses, bacteria, or parasites. People sometimes call gastroenteritis a stomach bug or stomach flu.

Some people also get gastroenteritis while traveling, which people call traveler’s diarrhea.

Viral gastroenteritis is highly contagious and spreads easily from person to person. The most common cause of gastroenteritis is norovirus, which takes 24–48 hours to incubate. This means a person can transmit the infection before they realize they are unwell.

The symptoms of gastroenteritis include:

  • abdominal pain and cramping
  • watery diarrhea
  • nausea or vomiting
  • sometimes, a fever

According to the NIDDK, most people recover from viral gastroenteritis in 1–3 days. However, some viruses can last between 1–2 weeks. These include adenovirus and rotavirus, which most often affect young children.

Food poisoning

Food poisoning occurs when someone eats or drinks contaminated food or water. Like gastroenteritis, viruses, bacteria, or parasites can cause food poisoning. However, unlike gastroenteritis, food poisoning is not contagious.

Food poisoning often occurs suddenly. Depending on the type of virus or bacteria a person ingests, it may develop 30 minutes to several weeks after eating the contaminated food. The most common symptoms include:

  • stomach cramps
  • nausea and vomiting
  • diarrhea
  • fever

Most people with food poisoning get better without treatment. However, the Centers for Disease Control and Prevention (CDC) state that older adults, children under 5, and people who are pregnant, or have weaker immune systems, are more likely to develop complications.

Medications

The NIDDK state that some medications can also cause vomiting and diarrhea as a side effect. These include antibiotics and antacids that contain magnesium.

Long-term antibiotic use can change the gut flora in the large intestine and cause chronic digestive problems. It can also increase the likelihood of a Clostridium difficile infection.

Other causes

These are many other causes of diarrhea and vomiting. Below is a list of causes and their symptoms.

CauseSymptoms
Hangoverdry mouth, thirst, headache, light and sound sensitivity, fatigue, nausea, vomiting, diarrhea
Anxietyrapid heartbeat, shortness of breath, sweating, feelings of stress or panic, vomiting, diarrhea
Food allergynausea, abdominal pain, vomiting, diarrhea, nasal congestion, itching, swelling of the lips
Food intoleranceflatulence, bloating, abdominal pains, nausea, vomiting, diarrhea, headaches
Influenza (flu)fever or chills, fatigue, cough, sore throat, body aches, headaches, vomiting and diarrhea
COVID-19fever, chills, cough, fatigue, loss of sense of smell or taste, congestion, diarrhea, vomiting
Diverticulitis abdominal pain, nausea, vomiting, diarrhea or constipation
Appendicitissevere abdominal pain, nausea, vomiting, diarrhea, fever, loss of appetite
Bowel obstructionpain that comes and goes, swollen and hard belly, vomiting, constipation or diarrhea
Adrenal insufficiency (Addison’s disease)muscle weakness, fatigue, weight loss, lack of appetite, fainting, mouth sores, nausea, vomiting, diarrhea
Anaphylaxisswollen throat or tongue, hives, difficulty breathing, dizziness or fainting, vomiting, and diarrhea
Pancreatic cancerabdominal pain, yellowing of the skin and eyes, loss of appetite, nausea, vomiting, diarrhea, greasy stools, weakness, weight loss

Appendicitis, bowel obstruction, anaphylaxis, and pancreatic cancer are serious conditions that require immediate medical treatment.

For temporary cases of vomiting and diarrhea, a person may not need any medical treatment. Symptoms caused by a hangover, anxiety, gastroenteritis, or food poisoning can resolve on their own.

Gradually replacing lost fluids and electrolytes can help a person recover. Once vomiting subsides, a person can start drinking sips of clear liquids, such as broth, diluted apple juice, herbal tea, or oral rehydration solutions.

After a person can tolerate liquids again, they can slowly introduce bland foods, such as crackers, bananas, plain rice, and applesauce. A person may find it easier to start with smaller, more frequent meals.

It is best to consult with a healthcare provider before taking over-the-counter antidiarrheal medications, as they can be dangerous for children. Also, people with blood in their stool should not take them.

Home remedies can help reduce the symptoms of vomiting and diarrhea. A person can try:

  • drinking ginger tea or ginger ale
  • sucking peppermint candies
  • taking zinc supplements, which can reduce the duration of diarrhea by 25%
  • taking an oral rehydration solution

Complications of diarrhea and vomiting include dehydration, electrolyte imbalances, fainting, and heart rhythm abnormalities.

Dehydration occurs when the body loses more water than it takes in. According to the World Health Organization (WHO), the early signs of dehydration include:

  • thirst
  • sunken eyes
  • restlessness or irritability

The signs of severe dehydration include:

  • lack of energy
  • skin that does not flatten quickly when pinched
  • unable to drink
  • unconsciousness

Young children can become dehydrated within a day after developing diarrhea and vomiting. The signs of dehydration in children include:

  • dry tongue and mouth
  • sunken eyes or cheeks
  • no tears when crying
  • no wet diaper for 3 or more hours

Anyone with the symptoms of severe dehydration requires emergency medical care. This is especially true for young children and vulnerable adults.

The NIDDK state that a person should also seek medical care right away if they:

  • see blood or pus in their stools
  • notice their stools are black or tarry
  • have a high fever
  • pass six or more loose stools per day
  • have severe stomach or rectal pain
  • lack energy or suddenly become irritable

Parents or caregivers should take a child to a doctor if they have these symptoms as well as any fever or diarrhea that lasts more than 1 day.

A person cannot prevent all causes of diarrhea and vomiting. However, there are things they can do to reduce the chances of developing gastroenteritis or food poisoning.

The CDC recommend the following practices to prevent food poisoning:

  • washing hands and kitchen surfaces often
  • rinsing fruits and vegetables before preparing them
  • keeping raw meat, seafood, fish, and eggs separate from all other food and use separate utensils, cutting boards, and plates for them
  • using a food thermometer to check that foods are cooked to the right temperature
  • putting perishable food in the refrigerator within 2 hours after use
  • thawing frozen food safely in the refrigerator

For gastroenteritis, a person can avoid contact with people who are sick and wash the hands for with soap and water regularly, particularly after using the bathroom, changing diapers, or before preparing meals.

Vomiting and diarrhea have many potential causes, but viruses, food poisoning, and medications are common. If the symptoms are frequent and occur after meals, a person may have a food intolerance or allergy.

However, some causes of vomiting and diarrhea are more serious. People with severe pain, symptoms of dehydration, and chronic vomiting or diarrhea should seek help from a doctor.