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 significant loss of body fluid (dehydration). 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
Gastroenteritis (infection of the digestive tract) due to a virus
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, ingestion of a toxic substance (such as large amounts of , iron, or alcohol), and frequent use of cannabis (marijuana).
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
Bright green or bloody vomit
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. 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.
Testing
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.
Fluids
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
Diet
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
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 bloody stools).
