Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Vomiting in Infants and Children


Deborah M. Consolini

, MD, Sidney Kimmel Medical College of Thomas Jefferson University

Last full review/revision Jun 2020| Content last modified Jun 2020
Click here for the Professional Version
Topic Resources

Vomiting is the uncomfortable, involuntary, forceful throwing up of food. In infants, vomiting must be distinguished from spitting up. Infants often spit up small amounts while being fed or shortly afterward—typically while being burped. Spitting up may occur because infants feed rapidly, swallow air, or are overfed, but it may occur for no apparent reason. Vomiting is typically caused by a disorder. Experienced parents can usually tell the difference between spitting up and vomiting, but first-time parents may need to talk to a doctor or nurse.

Vomiting can cause dehydration because fluid is lost. Sometimes children cannot drink enough to make up for lost fluid—either because they are continuing to vomit or because they do not want to drink. Children who are vomiting usually do not want to eat, but this lack of appetite rarely causes a problem.

(See also Nausea and Vomiting in adults.)

Causes of Vomiting in Infants and Children

Vomiting can be beneficial by getting rid of toxic substances that have been swallowed. However, vomiting is most often caused by a disorder. Usually, the disorder is relatively harmless, but occasionally vomiting is a sign of a serious problem, such as a blockage in the stomach or intestine or increased pressure within the skull (intracranial hypertension).

Common causes

Likely causes of vomiting depend on the child’s age.

In newborns and infants, the most common causes of vomiting include

In older children, the most common cause is

  • Gastroenteritis due to a virus

Less common causes

In newborns and infants, some causes, although less common, are important because they may be life threatening:

  • Narrowing or blockage of the passage out of the stomach (pyloric stenosis) in infants aged 3 to 6 weeks

  • A blockage of the intestine caused by birth defects, such as twisting (volvulus) or narrowing (stenosis) of the intestine

  • Sliding of one segment of intestine into another (intussusception) in infants aged 3 to 36 months

Food intolerance, allergy to cow's milk protein, and certain uncommon hereditary metabolic disorders may also cause vomiting in newborns and infants.

In older children and adolescents, rare causes include serious infections (such as a kidney infection or meningitis), acute appendicitis, or a disorder that increases pressure within the skull (such as a brain tumor or a serious head injury). In adolescents, causes also include gastroesophageal reflux disease or peptic ulcer disease, food allergies, cyclic vomiting, a slowly emptying stomach (gastroparesis), pregnancy, eating disorders, and ingestion of a toxic substance (such as large amounts of acetaminophen, iron, or alcohol).

Evaluation of Vomiting in Infants and Children

For doctors, the first goal is to determine whether children are dehydrated and whether the vomiting is caused by a life-threatening disorder.

Warning signs

The following symptoms and characteristics are cause for concern:

  • Lethargy and listlessness

  • In infants, inconsolability or irritability and bulging of the soft spots (fontanelles) between the skull bones

  • In older children, a severe headache, stiff neck that makes lowering the chin to the chest difficult, sensitivity to light, and fever

  • Abdominal pain, swelling, or both

  • Persistent vomiting in infants who have not been growing or developing as expected

  • Bloody stools

When to see a doctor

Children with warning signs should be immediately evaluated by a doctor, as should all newborns; children whose vomit is bloody, resembles coffee grounds, or is bright green; and children with a recent (within a week) head injury. Not every tummy ache counts as abdominal pain (the warning sign). However, if children appear uncomfortable even when not vomiting and their discomfort lasts more than a few hours, they should probably be evaluated by a doctor.

For other children, signs of dehydration, particularly decreased urination, and the amount they are drinking help determine how quickly they need to be seen. The urgency varies somewhat by age because infants and young children can become dehydrated more quickly than older children. Generally, infants and young children who have not urinated for more than 8 hours or who have been unwilling to drink for more than 8 hours should be seen by a doctor.

The doctor should be called if children have more than 6 to 8 episodes of vomiting, if the vomiting continues more than 24 to 48 hours, or if other symptoms (such as cough, fever, or rash) are present.

Children who have had only a few episodes of vomiting (with or without diarrhea), who are drinking at least some fluids, and who otherwise do not appear very ill rarely require a doctor’s visit.

What the doctor does

Doctors first ask questions about the child's symptoms and medical history. Doctors then do a physical examination. A description of the child's symptoms and a thorough examination usually enable doctors to identify the cause of vomiting (see Table: Some Causes and Features of Vomiting in Infants, Children, and Adolescents).

Doctors ask

  • When the vomiting started

  • How often it occurs

  • What the vomit looks like (including its color)

  • Whether it is forceful (projectile)

  • How much is vomited

Determining whether there is a pattern—occurring at certain times of the day or after eating certain foods—can help doctors identify possible causes. Information about other symptoms (such as fever and abdominal pain), bowel movements (frequency and consistency), and urination can also help doctors identify a cause.

Doctors also ask about recent travel, injuries, and, for sexually active adolescent girls, use of birth control.

A physical examination is done to check for clues to possible causes. Doctors note whether children are growing and developing as expected.


Some Causes and Features of Vomiting in Infants, Children, and Adolescents


(listed from most to least common)

Common Features*


In infants

Usually with diarrhea (which rarely is bloody)

Sometimes a fever

Sometimes recent contact with infected people (as at a day care center), with animals at a petting zoo (where Escherichia [E.] coli may be acquired), or with reptiles (which may be infected with Salmonella bacteria) or recent consumption of undercooked, contaminated food or contaminated water

A doctor’s examination

Sometimes examination and culture of stool

Symptoms that occur after feeding, including fussiness, spitting up, arching of the back, crying, or a combination

Sometimes a cough when lying down, poor weight gain, or both

A doctor's examination

Sometimes treatment with drugs to suppress acid production (if symptoms are relieved, the cause is probably gastroesophageal reflux)

Sometimes x-rays of the upper digestive tract after barium is given by mouth (upper GI series)

Sometimes endoscopy

Pyloric stenosis (narrowing or blockage of the passage out of the stomach)

Forceful (projectile) vomiting that occurs immediately and after all feedings in infants aged 3–6 weeks

Signs of dehydration, an emaciated appearance, or both

In infants, appearing hungry and feeding eagerly

More common among boys, especially first-born boys

Ultrasonography of the stomach

If ultrasonography is unavailable or inconclusive, upper GI series

Birth defects that cause narrowing (stenosis) or blockage (atresia) of the digestive tract

Delayed passage of the first bowel movement (called meconium)

A swollen abdomen

Bright green or yellow vomit, indicating bile, during the first 24–48 hours of life (if the digestive tract is blocked) or somewhat later (if it is only narrowed)

More common among infants who have Down syndrome or whose mother had too much amniotic fluid in the uterus during pregnancy

An x-ray of the abdomen

Upper GI series or x-rays of the lower digestive tract after insertion of barium into the rectum (barium enema), depending on the suspected location of the problem

Intussusception (sliding of one segment of intestine into another)

Crying that occurs in bouts every 15–20 minutes, with children often drawing their legs up to their chest

Later tenderness of the abdomen when it is touched and bowel movements that look like currant jelly (because they contain blood)

Typically in children 3–36 months old

Insertion of air into the rectum (air enema)

Sometimes ultrasonography of the abdomen

Malrotation (abnormal development of the intestine, resulting in its being abnormally located and increasing the likelihood it will twist on itself)

Bright green or yellow vomit (indicating bile), a swollen abdomen, and blood in stool

Often in newborns

An x-ray of the abdomen

Upper GI series or barium enema

Fever and lethargy

A complete blood cell count

Culture of blood, urine, and cerebrospinal fluid

A chest x-ray if children have breathing problems

Diarrhea or constipation

Poor feeding

Weight loss, poor growth, or both

Blood in stools

Symptoms that lessen when the formula is changed

Possibly endoscopy, colonoscopy, or both

Poor feeding and not growing or developing as expected (failure to thrive)

Sluggishness (lethargy)

Other features depending on the disorder, such as

  • Jaundice

  • Cataracts

  • Unusual body and urine odors

Screening all newborns using a small sample of blood obtained by pricking the heel

Blood tests to measure levels of electrolytes (minerals necessary to maintain fluid balance in the body), ammonia, and glucose

Other tests based on the suspected cause

In children and adolescents

Usually with diarrhea (which rarely is bloody)

Sometimes fever

Sometimes recent contact with infected people (as at a day care center, at a camp, or on a cruise), with animals at a petting zoo (where Escherichia [E.] coli may be acquired), or with reptiles (which may be infected with Salmonella bacteria) or recent consumption of undercooked, contaminated food or contaminated water

A doctor’s examination

Sometimes examination or culture of stool


Pain in the chest or upper abdomen

Symptoms that worsen when lying down or after eating

Sometimes a nighttime cough

A doctor's examination

Symptoms that lessen or are relieved after treatment with drugs to suppress acid production

Sometimes upper GI series

Sometimes endoscopy

Gastroparesis or delayed gastric emptying (the stomach empties slowly)

Feeling of fullness after eating only small amounts

Sometimes a recent viral illness

A doctor's examination

Upper GI series or x-rays taken after formula or food is given by mouth (gastric emptying scan)

Vomiting that occurs immediately after eating certain food

Often hives, lip or tongue swelling, difficulty breathing, wheezing, abdominal pain, diarrhea, or a combination

A doctor's examination

Sometimes allergy testing

Avoidance of a particular food to see whether symptoms stop

Infections in parts of the body other than the digestive tract


Often symptoms that suggest the location of the infection, such as headache, ear pain, sore throat, swollen lymph nodes in the neck, pain during urination, pain in the side (flank), or a runny nose

A doctor’s examination

Sometimes tests based on the suspected cause

Initially a general feeling of illness and discomfort in the middle of the abdomen, followed by pain moving to the lower right part of the abdomen

Then vomiting, loss of appetite, and fever

Ultrasonography or CT of the abdomen

Increased pressure within the skull (intracranial hypertension), caused by a tumor or an injury

Waking up because of a headache during the night or waking in the morning with a headache

Headaches that become progressively worse and are made worse by coughing or bowel movements

Sometimes changes in vision and difficulty walking, talking, or thinking

CT of the brain

Recurring episodes of vomiting separated by periods of wellness

Often headaches associated with vomiting

Often a family history of migraines

A doctor's examination

Sometimes tests to rule out other causes of recurring episodes of vomiting

Purposefully eating too little to lose weight or eating too much (bingeing) followed by purposefully vomiting or taking laxatives (purging)

Erosion of enamel on teeth and scars on the hands from using them to trigger vomiting

A distorted body image

A doctor’s examination

No menstrual periods

Morning sickness, bloating, and tender breasts

Sexual activity (although many adolescents deny it) with no or inadequate use of birth control

A urine pregnancy test

Ingestion of a toxin such as large amounts of acetaminophen, iron, or alcohol

Various features depending on the substance

Often a history of taking the substance

Blood tests to measure levels of the substance

* Features include symptoms and results of the doctor's examination. Features mentioned are typical but not always present.

CT = computed tomography; GI = gastrointestinal.


Doctors choose tests based on suspected causes suggested by results of the examination. Most children do not require testing. However, if abnormalities in the abdomen are suspected, imaging tests are typically done. If a hereditary metabolic disorder is suspected, blood tests specific for that disorder are done.

If dehydration is suspected, blood tests to measure electrolytes (minerals necessary to maintain fluid balance in the body) are sometimes done.

Treatment of Vomiting in Infants and Children

If a specific disorder is the cause, it is treated. Vomiting caused by gastroenteritis usually stops on its own.


Making sure children are well-hydrated is important. Fluids are usually given by mouth (see Dehydration in Children). Oral rehydration solutions that contain the right balance of electrolytes are used. In the United States, these solutions are widely available without a prescription from most pharmacies and from supermarkets. Sports drinks, sodas, juices, and similar drinks have too little sodium and too much carbohydrate and should not be used.

Even children who are vomiting frequently may tolerate small amounts of solution that are given often. Typically, 1 teaspoon (5 milliliters) is given every 5 minutes. If children keep this amount down, the amount is gradually increased. With patience and encouragement, most children can take enough fluid by mouth to avoid the need for fluids by vein (intravenous fluids). However, children with severe dehydration and those who do not take enough fluid by mouth may need intravenous fluids.

Drugs to reduce vomiting

Drugs frequently used in adults to reduce nausea and vomiting are less often used in children because their usefulness has not been proved. Also, these drugs may have side effects that include drowsiness, dizziness, headache, and constipation. However, if nausea or vomiting is severe or does not go away, doctors may give promethazine, prochlorperazine, metoclopramide, or ondansetron to children who are over 2 years of age.


As soon as children have received enough fluid and are not vomiting, they should be given an age-appropriate diet. Infants may be given breast milk or formula.

Key Points about Vomiting in Infants and Children

  • Usually, vomiting is caused by gastroenteritis due to a virus and causes no long-lasting or serious problems.

  • Sometimes, vomiting is a sign of a serious disorder.

  • If diarrhea accompanies vomiting, the cause is probably gastroenteritis.

  • Children should be evaluated by a doctor immediately if vomiting persists or they have any warning signs (such as lethargy, irritability, a severe headache, abdominal pain or swelling, vomit that is bloody or bright green or yellow, or bloody stools).

Drugs Mentioned In This Article

Generic Name Select Brand Names
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID