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Nausea and 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
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Topic Resources

Nausea is the sensation of impending emesis and is frequently accompanied by autonomic changes, such as increased heart rate and salivation. Nausea and vomiting typically occur in sequence; however, they can occur separately (eg, vomiting can occur without preceding nausea as a result of increased intracranial pressure).

Vomiting is uncomfortable and can cause dehydration because fluid is lost and because the ability to rehydrate by drinking is limited.


Vomiting is the final part of a sequence of events coordinated by the emetic center located in the medulla. The emetic center can be activated by afferent neural pathways from digestive (eg, pharynx, stomach, small bowel) and nondigestive (eg, heart, testes) organs, the chemoreceptor trigger zone located in the area postrema on the floor of the 4th ventricle (containing dopamine and serotonin receptors), and other central nervous system centers (eg, brain stem, vestibular system).


The causes of vomiting vary with age and range from relatively benign to potentially life threatening (see Table: Some Causes of Vomiting in Infants, Children, and Adolescents). Vomiting is a protective mechanism that provides a means to expel potential toxins; however, it can also indicate serious disease (eg, intestinal obstruction). Bilious vomiting indicates a high intestinal obstruction and, especially in an infant, requires immediate evaluation.


Infants normally spit up small amounts (usually < 5 to 10 mL) during or soon after feedings, often when being burped. Rapid feeding, air swallowing, and overfeeding may be causes, although spitting up occurs even without these factors. Occasional vomiting may also be normal, but repeated vomiting is abnormal.

The most common causes of vomiting in infants and neonates include the following:

Other important causes in infants and neonates include the following:

Less common causes of recurrent vomiting include sepsis and food intolerance. Metabolic disorders (eg, urea cycle disorders, organic acidemias) are uncommon but can manifest with vomiting.

Older children

The most common cause is

Nongastrointestinal infections may cause a few episodes of vomiting. Other causes to consider include serious infection (eg, meningitis, pyelonephritis), acute abdomen (eg, appendicitis), increased intracranial pressure secondary to a space-occupying lesion (eg, caused by trauma or tumor), and cyclic vomiting.

In adolescents, causes of vomiting also include pregnancy, eating disorders, and toxic ingestions (eg, acetaminophen, iron, ethanol).


Some Causes of Vomiting in Infants, Children, and Adolescents


Suggestive Findings

Diagnostic Approach

Vomiting in infants

Usually with diarrhea

Sometimes fever and/or contact with a person who has similar symptoms

Clinical evaluation

Sometimes rapid immunoassays for viral antigens (eg, rotavirus, adenovirus)

Recurrent fussiness during or after feedings

Possibly poor weight gain, arching of the back, recurrent respiratory symptoms (eg, cough, stridor, wheezing)

Empiric trial of acid suppression

Sometimes upper GI contrast study, a milk scan, esophageal pH monitoring and/or impedance study, or endoscopy

Bacterial enteritis or colitis

Usually with diarrhea (often bloody), fever, crampy abdominal pain, distention

Often contact with a person who has similar symptoms

Clinical evaluation

Sometimes stool examination for white blood cell count and culture

Recurrent projectile vomiting immediately after feeding in neonates aged 2–12 weeks, infrequent stools

May be emaciated and dehydrated

Sometimes palpable “olive” in right upper quadrant

Ultrasonography of pylorus

Upper GI contrast study if ultrasonography is unavailable or uncertain

Congenital atresias or stenoses

Abdominal distention

Bilious emesis in first 24–48 hours of life (with lesser degrees of stenosis, vomiting can be delayed)

Sometimes polyhydramnios during pregnancy, Down syndrome, jaundice

Abdominal x-ray

Upper GI series or contrast enema depending on findings

Colicky abdominal pain, inconsolable crying, lethargy, drawing of legs up to chest

Later, bloody ("currant jelly") stool

Typically age 3–36 months, but can be outside this range

Abdominal ultrasonography

If ultrasonography is positive or nondiagnostic, air or contrast enema (unless patient has signs of peritonitis or perforation)

In neonates, delayed passage of meconium, abdominal distention, bilious emesis

Abdominal x-ray

Contrast enema

Rectal biopsy

Malrotation with volvulus

In neonates, bilious emesis, abdominal distention and pain

Bloody stool

Abdominal x-ray

Contrast enema or upper GI series

Fever, lethargy, tachycardia, tachypnea

Widened pulse pressure, hypotension

Cell counts and cultures (blood, urine, cerebrospinal fluid)

Chest x-ray if pulmonary symptoms are present

Abdominal pain, diarrhea

Possibly eczematous rash or urticaria

Elimination diet

Sometimes skin testing and/or radioallergosorbent testing (RAST)

Poor feeding, failure to thrive, lethargy, hepatosplenomegaly, jaundice

Sometimes unusual odor, cataracts

Electrolytes, ammonia, liver tests, blood urea nitrogen (BUN), creatinine, serum glucose, total and direct bilirubin, complete blood count, prothrombin time/partial thromboplastin time (PT/PTT)

Neonatal metabolic screening

Further specific tests based on findings

Vomiting in children and adolescents

Usually with diarrhea

Sometimes fever, contact with a person who has similar symptoms, or history of travel

Clinical evaluation

Sometimes rapid immunoassays for viral antigens (eg, rotavirus, adenovirus)

Bacterial enteritis or colitis

Usually with diarrhea (often bloody), fever, crampy abdominal pain, distention, fecal urgency

Often contact with a person who has similar symptoms or history of travel

Clinical evaluation

Sometimes stool for white blood cell count, culture

Non-GI infection


Often localizing findings (eg, headache, ear pain, sore throat, cervical adenopathy, dysuria, flank pain, nasal discharge) depending on cause

Clinical evaluation

Testing as needed for suspected cause

Initial general malaise and periumbilical discomfort followed by pain localizing to right lower quadrant, vomiting after pain manifestation, anorexia, fever, tenderness at McBurney point, decreased bowel sounds

Ultrasonography (preferred over CT to limit radiation exposure)

Serious infection

Fever, toxic appearance, back pain, dysuria (pyelonephritis)

Nuchal rigidity, photophobia (meningitis)

Listlessness, hypotension, tachycardia (sepsis)

Cell counts and cultures (blood, urine, cerebrospinal fluid) as indicated by findings

≥ 3 episodes of intense acute nausea and unremitting vomiting and sometimes abdominal pain or headache lasting hours to days

Intervening symptom-free intervals lasting weeks to months

Exclusion of metabolic, GI (eg, malrotation), or central nervous system (eg, brain tumor) disorders

Intracranial hypertension (caused by tumor or trauma)

Chronic, progressive headache; nocturnal awakenings; morning vomiting; headache worsened by coughing or Valsalva maneuver; vision changes

Brain CT (without contrast)

Binge and purge cycles, erosion of tooth enamel, weight loss or gain

Sometimes skin lesions on hand from inducing vomiting (Russell sign)

Clinical evaluation

Amenorrhea, morning sickness, bloating, breast tenderness

History of unprotected sexual activity†

Urine pregnancy test

Toxic ingestions (eg, acetaminophen, iron, ethanol)

Often history of ingestion

Various findings depending on ingested substance

Qualitative and sometimes quantitative serum drug levels (depending on substance)

Adverse drug reaction (eg, to chemotherapeutic drugs)

Exposure to a specific drug

Clinical evaluation

* Causes are listed in order of frequency.

† Many adolescents do not admit to sexual activity.

GI = gastrointestinal.


Evaluation includes assessment of severity (eg, presence of dehydration, surgical or other life-threatening disorder) and diagnosis of cause.


History of present illness should determine when vomiting episodes started, frequency, and character of episodes (particularly whether vomiting is projectile, bilious, or small in amount and more consistent with spitting up). Any pattern to the vomiting (eg, after feeding, only with certain foods, primarily in the morning or in recurrent cyclic episodes) should be established. Important associated symptoms include diarrhea (with or without blood), fever, anorexia, and abdominal pain, distention, or both. Stool frequency and consistency and urinary output should be noted.

Review of systems should seek symptoms of causative disorders, including weakness, poor suck, and failure to thrive (metabolic disorders); delay in passage of meconium, abdominal distention, and lethargy (intestinal obstruction); headache, nuchal rigidity, and vision changes (intracranial disorders); food bingeing or signs of distorted body image (eating disorders); missed periods and breast swelling (pregnancy); rashes (eczema or urticaria in food allergies, petechiae in sepsis or meningitis); ear pain or sore throat (focal nongastrointestinal infection); and fever with headache, neck or back pain, or abdominal pain (meningitis, pyelonephritis, or appendicitis).

Past medical history should note history of travel (possible infectious gastroenteritis), any recent head trauma, and unprotected sex (pregnancy).

Physical examination

Vital signs are reviewed for indicators of infection (eg, fever) and volume depletion (eg, tachycardia, hypotension).

During the general examination, signs of distress (eg, lethargy, irritability, inconsolable crying) and signs of weight loss (cachexia) or gain are noted.

Because the abdominal examination may cause discomfort, the physical examination should begin with the head. The head and neck examination should focus on signs of infection (eg, red, bulging tympanic membrane; bulging anterior fontanelle; erythematous tonsils) and dehydration (eg, dry mucous membranes, lack of tears). The neck should be passively flexed to detect resistance or discomfort, suggesting meningeal irritation.

Cardiac examination should note presence of tachycardia (eg, dehydration, fever, distress). Abdominal examination should note distention; presence and quality of bowel sounds (eg, high-pitched, normal, absent); tenderness and any associated guarding, rigidity, or rebound (peritoneal signs); and presence of organomegaly or mass.

The skin and extremities are examined for petechiae or purpura (severe infection) or other rashes (possible viral infection or signs of atopy), jaundice (possible metabolic disorder), and signs of dehydration (eg, poor skin turgor, delayed capillary refill).

Growth parameters and signs of developmental progress should be noted.

Red flags

The following findings are of particular concern:

  • Bilious emesis

  • Lethargy or listlessness

  • Inconsolability and bulging fontanelle in infant

  • Nuchal rigidity, photophobia, and fever in older child

  • Peritoneal signs or abdominal distention (surgical abdomen)

  • Persistent vomiting with poor growth or development

Interpretation of findings

Initial findings help determine severity of diagnosis and need for immediate intervention.

  • Any neonate or infant with recurrent or bilious (yellow or green) emesis or projectile vomiting most likely has a gastrointestinal obstruction and probably requires surgical intervention.

  • An infant or young child with colicky abdominal pain, signs of intermittent pain or listlessness, and absent or bloody stools needs to be evaluated for an intussusception.

  • A child or adolescent with fever, nuchal rigidity, and photophobia should be evaluated for meningitis.

  • A child or adolescent with fever and abdominal pain followed by vomiting, anorexia, and decreased bowel sounds should be evaluated for appendicitis.

  • Recent history of head trauma or chronic progressive headaches with morning vomiting and vision changes indicate intracranial hypertension.

Other findings can be interpreted primarily depending on age (see Table: Some Causes of Vomiting in Infants, Children, and Adolescents).

In infants, irritability, choking, and respiratory signs (eg, stridor) may be manifestations of gastroesophageal reflux. A history of poor development or neurologic manifestations suggests a central nervous system or metabolic disorder. Delayed passage of meconium, later onset of vomiting, or both may indicate Hirschsprung disease or intestinal stenosis.

In children and adolescents, fever suggests infection; the combination of vomiting and diarrhea suggests acute gastroenteritis. Lesions on fingers and erosion of tooth enamel or an adolescent unconcerned about weight loss or with distorted body image suggests an eating disorder. Morning nausea and vomiting, amenorrhea, and possibly weight gain suggest pregnancy. Vomiting that has occurred in the past and is episodic, short-lived, and has no other accompanying symptoms suggests cyclic vomiting.


Testing should be directed by suspected causative disorders (see Table: Some Causes of Vomiting in Infants, Children, and Adolescents). Imaging studies are typically done to evaluate abdominal or central nervous system pathology. Various specific blood tests or cultures are done to diagnose inherited metabolic disorders or serious infection.

If dehydration is suspected, serum electrolytes should be measured.


Treatment of nausea and vomiting is targeted at the causative disorder. Rehydration is important.

Drugs frequently used in adults to decrease nausea and vomiting are used less often in children because the usefulness of treatment has not been proved and because these drugs have potential risks of adverse effects and of masking an underlying condition. However, if nausea or vomiting is severe or unremitting, antiemetic drugs can be used cautiously in children > 2 years. Useful drugs include

  • Promethazine: For children > 2 years, 0.25 to 1 mg/kg (maximum 25 mg) orally, IM, IV, or rectally every 4 to 6 hours

  • Prochlorperazine: For children > 2 years and weighing 9 to 13 kg, 2.5 mg orally every 12 to 24 hours; for those 13 to 18 kg, 2.5 mg orally every 8 to 12 hours; for those 18 to 39 kg, 2.5 mg orally every 8 hours; for those > 39 kg, 5 to 10 mg orally every 6 to 8 hours

  • Metoclopramide: 0.1 mg/kg orally or IV every 6 hours (maximum 10 mg/dose)

  • Ondansetron: 0.15 mg/kg (maximum 8 mg) IV every 8 hours or, if the oral form is used, for children 2 to 4 years, 2 mg every 8 hours; for those 4 to 11 years, 4 mg every 8 hours; for those ≥ 12 years, 8 mg every 8 hours

Promethazine is an H1 receptor blocker (antihistamine) that inhibits the emetic center response to peripheral stimulants. The most common adverse effects are respiratory depression, sedation, dizziness, anxiety, blurred vision, dry mouth, impotence, and constipation; the drug is contraindicated in children < 2 years. Therapeutic doses of promethazine can cause extrapyramidal adverse effects, including torticollis.

Prochlorperazine is a weak dopamine receptor blocker that depresses the chemoreceptor trigger zone. Drowsiness, dizziness, anxiety, strange dreams, insomnia, galactorrhea, akathisia, and dystonia are the most common adverse effects.

Metoclopramide is a dopamine receptor antagonist that acts both centrally and peripherally by increasing gastric motility and decreasing afferent impulses to the chemoreceptor trigger zone. Drowsiness, dizziness, agitation, headache, diarrhea, akathisia, and dystonia are the most common adverse effects.

Ondansetron is a selective serotonin (5-HT3) receptor blocker that inhibits the initiation of the vomiting reflex in the periphery. A single dose of ondansetron is safe and effective in children who have acute gastroenteritis and do not respond to oral rehydration therapy (ORT). By facilitating ORT, this drug may prevent the need for IV fluids or, in children given IV fluids, may help prevent hospitalization. Typically, only a single dose is used because repeated doses can cause persistent diarrhea. Other common adverse effects include headache, dizziness, drowsiness, blurred vision, constipation, muscle stiffness, tachycardia, and hallucinations.

Key Points

  • In general, the most common cause of vomiting is acute viral gastroenteritis.

  • Associated diarrhea suggests an infectious gastrointestinal cause.

  • Bilious emesis, bloody stools, or lack of bowel movements suggests an obstructive cause.

  • Persistent vomiting (especially in an infant) requires immediate evaluation.

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