Pediatric Annals

Feature Article 

Vomiting Children: It's Not Always Gastroenteritis

Madeline Mier, MD; Amanda Nelson, MD; Leah Finkel, MD


Emesis is a common presentation in children. Many diagnostic considerations need to be made in a child with emesis and no diarrhea, particularly if lasting longer than 24 hours. The differential diagnosis includes trauma, increased intracranial pressure, obstruction, and metabolic abnormalities such as diabetic ketoacidosis. Prompt recognition with appropriate testing and management is needed. [Pediatr Ann. 2020;49(5):e233–e241.]


Emesis is a common presentation in children. Many diagnostic considerations need to be made in a child with emesis and no diarrhea, particularly if lasting longer than 24 hours. The differential diagnosis includes trauma, increased intracranial pressure, obstruction, and metabolic abnormalities such as diabetic ketoacidosis. Prompt recognition with appropriate testing and management is needed. [Pediatr Ann. 2020;49(5):e233–e241.]

A child who is vomiting is a common presentation among the pediatric population in both inpatient and outpatient settings. There are a range of disorders that can cause vomiting, from mild and self-limiting conditions to life-threatening ones, and often numerous organ systems may be involved. Understanding the pathophysiology of vomiting can help formulate an appropriate differential diagnosis. Vomiting is often caused by two mechanisms: mechanical (such as obstruction, over-distension from feeding, or mass effect), or triggered chemo-sensors (including M1, D2 and 5-HT).1 These chemosensors can detect toxins and drugs in the systemic circulation, which can trigger emesis.1 Medications such as ondansetron and diphenhydramine work at these chemoreceptors to stop the vomiting response.1

Patients seeking care will often be experiencing either acute or acute- on-chronic vomiting. Patients with chronic vomiting, or vomiting that has been occurring over a course of weeks to months, will generally first seek treatment from their primary care provider in the outpatient setting. This article focuses on the acute presentation of vomiting and its differential diagnosis, and also briefly addresses the chronic causes of vomiting.


It is first essential to determine if what is being described as “vomiting” is truly vomiting. The best descriptor of vomiting is a forceful expulsion of gastric contents associated with contraction of the abdominal and chest wall musculature.2 A parent will often use the word “vomit” to describe what is most likely “spit-up” in an infant. An infant's “spit-up” is better described as non-forceful expulsion of contents that often dribbles out of the infant's mouth and consists of food, such as breast milk or formula. This is in contrast to infants who present with forceful expulsion of food, which should make providers consider an abdominal pathology such as a bowel obstruction or pyloric stenosis. The next set of questions asked by the provider should help them identify the contents of the vomitus. Questions that may be helpful include “what color is the vomitus?” This can help providers identify if it is bilious or bloody emesis. Another question should be “what is in the vomit?” This can allow providers to understand if there are food particles present.

Another key history item to gather from the patient and family is the time-line of vomiting episodes. Is the vomiting acute (ie, ranging from hours to a few days), or has it been ongoing for days to weeks? How many times has the child vomited and how much? What time of day does it occur (such as immediately after awakening or after meals)? With what triggers, if any, does the vomiting happen or is there any association with eating? Worrisome characteristics of vomiting secondary to increased intracranial pressure include emesis that occurs early in the morning or awakens a child out of sleep (Figure 1). Pyloric stenosis, another concerning pathology, will often start as occasional, forceful vomiting that becomes progressively more frequent and occur after meals or feeds (Figure 2). These questions also allow clinicians to determine the risk of complications from vomiting that a patient may be experiencing, including dehydration or electrolyte abnormalities. Children with acute voluminous vomiting or prolonged vomiting will be more at risk for such complications.

Brain mass (see arrow pointing at mass). Used with permission from Dr. Shamim Ejaz (Department of Radiology, University of Illinois at Chicago).

Figure 1.

Brain mass (see arrow pointing at mass). Used with permission from Dr. Shamim Ejaz (Department of Radiology, University of Illinois at Chicago).

Pyloric stenosis (see arrow pointing at thickened pylorus). Used with permission from Dr. Shamim Ejaz (Department of Radiology, University of Illinois at Chicago).

Figure 2.

Pyloric stenosis (see arrow pointing at thickened pylorus). Used with permission from Dr. Shamim Ejaz (Department of Radiology, University of Illinois at Chicago).

Identifying other associated symptoms will help providers develop an appropriate diagnosis. These have been organized below by organ system (Table 1).

Emesis Differential Diagnosis

Table 1.

Emesis Differential Diagnosis


Important key positives that may suggest infectious etiology are associated fever and diarrhea, other family members with similar symptoms, upper respiratory infection symptoms, or recent travel. Perhaps the most common infectious etiology of vomiting among all age groups is viral gastroenteritis. Typically, the vomiting is associated with fever and diarrhea, and there may be other family members or children in the household with similar symptoms. It may also be associated with symptoms of upper respiratory tract infection such as cough, nasal congestion, or rhinorrhea.

Another common infectious cause of vomiting in younger children is a urinary tract infection, so including questions about dysuria, increased urinary frequency, or suprapubic pain is important. In adolescents, associated right upper quadrant pain after meals can indicate gallbladder pathology such as cholecystitis. In children and adolescents, abdominal pain localized to the periumbilical region or right lower quadrant with associated fever and vomiting can indicate appendicitis.


Questions should also include those aimed at identifying constipation, as this alone can cause vomiting. Helpful information for providers to obtain includes the date of the patient's last bowel movement, typical frequency of bowel movements, the consistency of stools, and if there is any straining with bowel movements. Clinicians should suspect constipation if bowel movements are hard or rock-like, infrequent, and associated with straining. Other pertinent positives that suggest gastrointestinal pathology are those that are worrisome for obstruction, as gastrointestinal obstruction is possible in any age group. Symptoms may include abdominal pain and forceful, bilious emesis. Children at risk for obstruction include those with prior abdominal surgeries, but it is not necessary for physicians to consider obstruction.


Symptoms that may suggest neurologic pathology include history of head trauma, vision changes, and changes in mental status or known underlying chronic neurologic diseases that can increase intracranial pressure, such as hydrocephalus. The presentation varies depending on the age of the child, so identifying any neurological changes by history and doing a thorough physical examination is essential. These different presentations are discussed below.


In the infant presenting with acute vomiting, providers must ensure there is no known underlying congenital or inborn error of metabolism. A good screening question for families is to ask if the child's newborn screen was normal. If they are unsure, it would be reasonable to obtain this information from their primary hospital or the state health department if available. Another common metabolic cause of vomiting in pediatrics is diabetic ketoacidosis. This can present with vomiting, and also with bdominal pain as well. Other associated pertinent positives are recent weight loss, polyuria, and polydipsia. Generally, if the cause of vomiting is metabolic, the child will be ill-appearing and can quickly become unstable, as they are often severely volume depleted.

Hydration and Mental Status

The last piece of history clinicians must obtain includes questions that aid in assessing the patient's hydration and mental status. Questions that parents are typically able to answer include how many ounces of liquid the patient has consumed in the past 24 hours, how many wet diapers they have had, any mental status changes, and any increased irritability, or lethargy. Asking about tear production or weight changes can be helpful as well. If available, providers should review the child's overall growth chart to quickly identify any acute changes. The provider needs to be mindful of red flags listed in Table 2.

Emesis Red Flags and Diagnoses to Consider

Table 2.

Emesis Red Flags and Diagnoses to Consider

Physical Examination

Information gathered from the patient's history should allow clinicians to perform a focused physical examination. For every pediatric patient, a close examination of vital signs is essential. These data can help physicians determine the patient's hydration status and if they are stable enough for further evaluation in an outpatient setting. Tachycardia and hypotension can be suggestive of hypovolemia and should make providers contemplate if transfer is needed. Hypotension is an ominous indicator of impending distress. Orthostatic hypotension can be diagnosed easily in any medical setting. True orthostatic hypotension is defined as a sustained reduction of systolic blood pressure more than 20 mm Hg or of diastolic blood pressure more than 10 mm Hg within 3 minutes of standing.3 Secondly, initial general examination should be taken into account. Does the child have altered mental status or appear acutely ill? Signs of dehydration can include dry mucus membranes, sunken fontanelle in infants, sunken eyes, delayed capillary refill beyond 2 seconds, and lack of tear production or skin mottling.

Abdominal examination should include inspection to look for distention. Palpation will help identify if there is localized abdominal pain or tenderness. Localization allows clinicians to better identify the likely area of the gastrointestinal tract that may be affected. For example, if pain is severe and generalized, this can suggest obstruction; right lower quadrant pain, in contrast, is more suggestive of an appendicitis. If providers detect organomegaly via abdominal palpation, this can suggest malignancy, acute infection of the enlarged organ, or metabolic disease.

Neurologic examination, including reflexes, palpation of the fontanelle in infants to see if bulging, gait (if the patient is ambulatory), muscle bulk and tone, and ocular examination looking for papilledema are essential to help determine if the etiology of vomiting is neurologic. Lastly, a thorough skin inspection should be done on patients of all ages to look for signs that may be suggestive of trauma (eg, bruising, petechiae, scratch marks, swelling).

Differential Diagnosis

Using the pertinent positives and negatives obtained via the history and physical examination, clinicians can then develop a targeted differential diagnosis. The easiest way to initiate a differential diagnosis in the pediatric patient is by age group. We discuss both the more common etiologies and the most alarming etiologies for neonates and young infants, toddlers and children, and adolescents.

There are a few common etiologies that span all age groups.4,5 Gastroenteritis is a common infectious cause of vomiting in the pediatric population. Typical associated symptoms are fever, upper respiratory infection symptoms, diarrhea, and potential contact with someone with similar symptoms. In younger infants, parents may report decreased oral intake, fewer wet diapers, and some irritability. As the child gets older, they may be better able to manage their fluid status, but nevertheless can still present with dehydration. The most common etiology of gastroenteritis is viral, regardless of age.

A second cause that is common among children and adolescents is appendicitis. It is essential to differentiate the key factors of appendicitis from viral gastroenteritis, as they can present similarly. Patients with appendicitis will often present with fever and abdominal pain that is either periumbilical with radiation to the right lower quadrant, or pain solely located in the right lower quadrant. This pain is often more localized than seen in viral gastroenteritis and is not usually associated with other infectious symptoms such as sick contacts or upper respiratory tract symptoms. An abdominal examination can be difficult in the younger age group, so maneuvers such as jumping up and down with the child can be helpful to identify peritoneal signs. If a child refuses to jump due to the pain or if jumping produces significant pain, this is suggestive of abdominal pathology, such as appendicitis or obstruction, and should be further investigated.

A third cause of vomiting that may be seen in all age groups is vomiting secondary to increased intracranial pressure. Although less common than gastroenteritis and appendicitis, it is essential to identify. Intracranial pressure will present differently based on the patient's age. In neonates and young infants, in addition to vomiting, they may present with increased irritability, regression or lack of achieving developmental milestones, or changes in tone. The vomiting may initially start as occasional and then progress to become more persistent. On examination, a bulging anterior fontanelle may be appreciated. In older children and adolescents, symptoms suggestive of an intracranial process include vomiting that awakens them at night or occurs immediately after waking. They may be able to describe associated headaches, vision changes, or neurological changes such as ataxia. In additional to testing cranial nerves, a thorough funduscopic examination should be done to assess for papilledema.

Infants Younger than Age 6 Months

In stable, well-appearing infants the most common etiology of vomiting is gastroesophageal reflux. Caregivers will often describe this as “spit-up” and state it looks like milk or partially digested milk. The vomiting is associated with meals and often can be triggered by overfeeding. In almost all cases, the physical examination is unremarkable and the baby is well-appearing. This can occur anytime in the neonatal period and will often extend through the first year of life. Parents may describe “gassiness” in association with this, but rarely are there other associated symptoms. Another common cause of vomiting in relationship to feeding is food protein enterocolitis. Parents will often complain of vomiting with feeds and seeing small specks of blood on the infant's stool. Usually the infant is well-appearing but may be struggling to gain weight appropriately.

An additional common etiology of vomiting in infants, as previously mentioned, is gastroenteritis. Infants may range from being well-appearing to severely dehydrated depending on the course of the illness. This is often associated with fever, diarrhea, and poor feeding; they may also have known sick contacts. It is important to mention that this should be differentiated from vomiting secondary to a urinary tract infection. It is difficult to delineate in infants younger than age 6 months with a fever and vomiting because providers are unable to assess for abdominal pain and localization. In patients in whom viral gastroenteritis is suspected, an evaluation of the urine should also be done because they may present similarly.

In a vomiting newborn who has not passed meconium in the first 48 hours of postnatal life, providers must consider Hirschsprung's disease or meconium ileus as the potential cause for obstruction. On rectal examination in Hirschprung's disease, physicians may note an expulsion of stool from the rectum. This is a positive “blast sign.” In comparison, meconium ileus may be displayed as an accumulation of meconium on abdominal radiograph. Regardless, if a neonate has not passed stool in the first 48 hours, further testing is warranted.

An ill-appearing infant, particularly if younger than age 3 months, presenting with symptoms such as fever, acute weight loss or lack of weight gain, hemodynamic instability, poor feeding, irritability, and changes in the fontanelle or mental status should alert physicians to be concerned for sepsis, inborn errors of metabolism, meningitis, or adrenal insufficiency until proven otherwise. Although these are not necessarily the most common causes of vomiting in the neonate, they do require immediate intervention and likely transfer to an emergency department.

Another cause of an ill-appearing, vomiting infant is gastrointestinal obstruction. In infants, the etiology is most likely malrotation. These infants may be fussier than usual, and abdominal palpation may make them more agitated. The abdomen may also appear distended. Obstruction can occur from days after birth to months later, and the underlying etiology may vary. Pyloric stenosis, a form of obstruction, is another pathologic cause of vomiting in the infant and typically presents between ages 6 and 8 weeks. Parents or caregivers will often describe the vomitus as forceful or projectile, non-bilious, and occurring after feeds. The course of the vomiting is progressive. Parents may initially think it is spit-up, but as the disease progresses the vomiting occurs with every feed and becomes more severe. Parents will often describe these children as eager to feed again soon after the vomiting episode. Physical examination can range from benign to significant for weight loss, dehydration, and change in mental status. Sometimes providers may be able to palpate an “olive-like” mass in the abdomen, but lack of this finding should not change clinical suspicion.

Another emergent cause of vomiting in the young infant is increased intracranial pressure. There are different causes of increased pressure, but in this age group it is more commonly meningitis, hydrocephalus, space-occupying lesions, or intraventricular hemorrhage. As mentioned before, this etiology of vomiting is common to all age groups but can present differently. Key history items that should alert providers to consider this etiology include neurologic changes or altered mental status, fever, and an infant with a history of prematurity, intracranial pathology (such as history of intracranial hemorrhage), or prior neurosurgical procedure (including placement of an intraventricular shunt). Neurologic changes clinicians may note on examination include an ill-appearing infant, inappropriate tone or reflexes, ophthalmologic changes, and/or a bulging fontanelle. Increased intracranial pressure can also be caused by trauma, both accidental and non-accidental. If parents report history of a fall, providers must determine the patient's risk for intracranial hemorrhage. A helpful tool for clinicians is the Pediatric Emergency Care Applied Research Network (PECARN) score, which helps identify patients who should receive further imaging (such as non-infusion head computed tomography). Conversely, physicians should suspect non-accidental trauma if the history the caregivers provide is inconsistent or if the injury is not reasonable for the explanation provided.

Older Infants and Children

The most common cause of vomiting in infants and children older than age 6 months is gastroenteritis. It is typically viral, but bacterial causes do exist. Often, the vomiting is associated with nausea, fever, and diarrhea. These patients can develop complications such as dehydration or electrolyte abnormalities depending on the severity of the course. As previously discussed, viral gastroenteritis must be differentiated from appendicitis. Appendicitis in this age group can also present with vomiting, fever, and nausea. The key differentiator is that in appendicitis the patient will likely report abdominal pain that is localized to the periumbilical region or pain localized to the right lower quadrant. In an ambulatory child, having them jump up and down with providers can be a good distraction for the child. Some children will do this task easily without pain, as compared to children with peritoneal signs who may refuse to do this out of pain or have exacerbation of their pain with this movement.

Other common causes of vomiting, although not infectious, include post-tussive vomiting and constipation. Posttussive vomiting in children this age occurs during upper respiratory tract illnesses when the child may have a cough, nasal congestion, and rhinorrhea. The vomiting is triggered by a coughing fit and the vomitus often contains mostly mucus or phlegm. Rarely does this etiology of vomiting cause more serious complications such as dehydration or electrolyte abnormalities. Constipation often presents with hard, infrequent stools that can be associated with straining during bowel movements or even blood on the external surface of the stool.

Abdominal obstruction, as previously mentioned, is common to all age groups but the etiology of the obstruction varies. In older infants and young children, intussusception is the most common cause of intestinal obstruction. A typical history for intussusception is the presence of abdominal pain that is episodic and crampy, which may be associated with vomiting or diarrhea. The child will often bring their knees to their chest during these episodes. Once the episodic pain has stopped, the child will be calm and well-appearing. The pain is often located near the right upper quadrant, but a child may not be able to verbalize this. It is possible the child will develop blood in their stool; however, this is a late-presenting symptom.

In this age group, children may present with vomiting that is due to diabetic ketoacidosis. This is often how a child with type 1 diabetes mellitus first presents with the disease. Other associated symptoms include diffuse abdominal pain, altered mental status, polyuria, polydipsia, and weight loss.

Acute episodes of vomiting may also be due to ingestion. Ingestion may not be witnessed but if parents have any sort of suspicion it should be taken seriously and a thorough inventory of the medications and chemicals in the home should be done. Vomiting may be the only initial presenting symptom, but the child can quickly decompensate depending on the toxin ingested. Other associated symptoms can include shortness of breath, altered mental status, skin rash, angioedema, and diarrhea. If this possibility is included on the clinicians' differential diagnosis, a detailed history of all prescribed and over-the-counter medications, their dosages and quantities, as well as other ingestible toxins in the home should be recorded.

Similarly, acute vomiting can be due to anaphylaxis. Providers should be concerned about this if a child has a known food or insect allergy and the parents suspect ingestion or exposure to these known allergens. Anaphylaxis typically occurs minutes to hours after ingestion of a food or medication. The initial presentation may include a variety of systemic symptoms, such as vomiting, shortness of breath, respiratory distress, diarrhea, swelling of lips or other parts of the airway, or skin changes. The course of anaphylaxis, like ingestion, can progress rapidly.

In this age group, the cause of increased intracranial pressure that can lead to vomiting is typically meningitis or a space-occupying lesion. The vomiting can awaken the child at nighttime or only occur in the morning. Parents may note personality changes, changes in the child's gait, or ophthalmologic changes. An older child may be able to describe a headache or vision changes. The physical examination can be benign; however, it should not limit providers from pursuing further testing if this etiology is suspected.


Adolescents can have many of the previously mentioned etiologies of vomiting, including appendicitis, viral gastroenteritis, and obstruction. However, the first evaluation of any vomiting, menstruating adolescent girl should be for pregnancy. Once that has been ruled out, then it is possible to consider the other etiologies. Viral gastroenteritis and appendicitis present similarly in adolescents as they do in children. The typical presentation includes fever, abdominal pain, and vomiting. As discussed above, appendicitis is often more associated with localization of the abdominal pain to the right lower quadrant, whereas viral gastroenteritis generally is associated with other viral symptoms such as nasal congestion, cough, diarrhea, or sick contacts.

Adolescents also can have vomiting due to gastrointestinal conditions such as pancreatitis. Pancreatitis is often associated with pain in the epigastric region. This can present similarly to gastritis, which also has epigastric pain; often, the pain and vomiting are associated with meals. The examination can be benign.

More urgent causes of vomiting in the adolescent population are ingestion (both accidental and non-accidental) and increased intracranial pressure. Any adolescent with vomiting plus altered mental status, changes in behavior, or new-onset seizures should be evaluated for acute ingestion of illicit substances or alcohol, regardless of what is elicited from the history. If the adolescent has neurologic changes in the presence of fever or other infectious symptoms, one should consider infectious neurologic processes such as meningitis or encephalitis. The last concerning neurologic etiology of vomiting in the adolescent population is increased intracranial pressure. Adolescents reporting visual changes, headaches, changes in gait, or morning vomiting should raise suspicion for an intracranial cause. A thorough neurologic and ophthalmologic examination should be performed, and the patient will likely require a higher level of care for further management.

Testing and Diagnostics

When evaluating a child with vomiting, after obtaining a history and performing a thorough physical examination, providers must determine if further, more in-depth testing is indicated. In most cases of well-appearing children with stable vital signs, no additional laboratory testing or imaging is needed. As noted above, the most common etiologies for vomiting in pediatric patients are benign, self-limiting conditions, so further diagnostics are often of little additional value. Furthermore, it is important to realize that the resources and personnel needed to conduct extensive testing are often limited in an outpatient setting, and the need for laboratory or imaging studies may often prompt transfer to a higher level of care.

However, in patients who present with a history of prolonged, severe emesis or with evidence of dehydration on examination, it is reasonable to obtain a basic metabolic panel to evaluate for electrolyte abnormalities.6 A point-of-care or serum glucose test is often valuable as well, particularly in younger children with a prolonged course of vomiting or those with signs of altered mental status, as this may uncover either hypo- or hyperglycemia. Similarly, serum lactate and ammonia can be helpful to rule out a metabolic etiology in patients who present with lethargy as well as vomiting. Any history of associated hematemesis should prompt evaluation of liver function and coagulation studies. In adolescent female patients, a urine or serum human chorionic gonadotropin should be performed to rule out pregnancy.

Although concurrent diarrhea is a common complaint in children who present with vomiting, stool studies are not necessary in every case. Indications for stool culture and/or polymerase chain reaction test include bloody or prolonged diarrhea, weight loss, or history of travel to tropical or other endemic regions. Similarly, stool ova and parasite studies may be useful in these patients as well, but otherwise have limited utility.7

In contrast, children who are not well-appearing and in whom a more serious diagnosis is suspected should undergo a more thorough evaluation, and obtaining initial laboratory results prior to transfer to an emergency department or admission to an inpatient setting can be crucial in effectively managing these patients. Any child suspected to be septic should have a complete blood count, blood culture, and inflammatory markers (erythrocyte sedimentation rate, C-reactive protein, or procalcitonin) done as soon as possible. In those for whom there is concern for meningitis or encephalitis, providers might consider performing a lumbar puncture for cerebral spinal fluid studies.

Additionally, most pediatric patients presenting with complaints of vomiting do not require further imaging studies or other testing. However, imaging is indicated in cases of bilious emesis, as well as for those patients in whom a more serious pathologic condition is suspected. Plain abdominal radiographs are often a reasonable first step and should include both upright and cross-table lateral views. Abdominal ultrasound is also an excellent imaging modality, particularly in cases of vomiting associated with localized abdominal pain, as it is noninvasive and can be helpful in diagnosis of a wide variety of conditions, including pyloric stenosis, cholecystitis, appendicitis, abdominal trauma, or intussusception. Patients whose clinical picture is concerning for increased intracranial pressure should urgently undergo a head computed tomography examination without infusion, and those with special considerations including ventriculoperitoneal shunts should have a shunt series or other specialized imaging and prompt transfer to a higher level of care (Table 3).

Imaging and Laboratory Studies to Help Guide Diagnosis for Acute Emesis

Table 3.

Imaging and Laboratory Studies to Help Guide Diagnosis for Acute Emesis

An electrocardiogram with a rhythm strip is helpful in children with severe dehydration and electrolyte abnormalities, as well as in those patients whose emesis is the result of certain intoxications or ingestions. Additionally, an upper gastrointestinal tract series can be beneficial in cases of suspected bowel obstruction. Further imaging and diagnostics are not routinely used in the testing of most children who present with complaints of emesis. The use of these modalities is generally limited to specific clinical presentations or use by consultants/subspecialists.

Treatment and Management

Management of acute vomiting in well-appearing pediatric patients most often consists of supportive care and symptomatic relief, as well as management of dehydration and other potential sequelae that may be present. In most children with acute gastroenteritis and mild to moderate dehydration, an emphasis should be placed on oral rehydration therapy.8 As a general rule, 50 mL/kg of an oral rehydration solution should be given over 4 hours to patients with mild dehydration, whereas 100 mL/kg should be given over the same time-frame to patients with moderate dehydration. Any patient in whom severe dehydration is suspected or in whom signs of shock are noted should immediately receive aggressive intravenous fluid resuscitation, including a 20-mL/kg bolus of isotonic crystalloid solution; additionally, admission to an inpatient setting or transfer to a higher level of care is generally indicated in these cases.

Children who are unable to tolerate oral intake due to profuse vomiting may benefit from a one-time dose of an anti-emetic, although medication should be withheld if the underlying cause of vomiting remains uncertain. Serotonin receptor antagonists, such as ondansetron, have been shown to be particularly effective in treating most causes of emesis in children older than age 6 months, and can allow for appropriate rehydration and prevent the need for intravenous fluids.9 Additionally, ondansetron is often an ideal choice for pediatric patients as it is available on most formularies as both an oral suspension and dissolving tablet.

In patients with suspected sepsis, broad-spectrum antibiotic therapy should be promptly initiated, even prior to transferring the patient for further evaluation and management. However, beyond cases of sepsis, antibiotics generally have a limited role in the treatment of most common causes of vomiting, including gastroenteritis and other infectious processes, and so are not routinely recommended. Many of these cases are viral in nature, and of those etiologies that are bacterial, many are toxin-mediated (eg, enterotoxigenic Escherichia coli) and the use of antibiotics can lead to increased toxin release and worsening of gastrointestinal symptoms. However, in patients with complaints of emesis and bloody diarrhea in which a specific pathogen has been identified, certain microbial infections (including Shigella, Campylobacter, and non-typhoidal Salmonella) may warrant appropriate antibiotic treatment.10


The decision to transfer a vomiting patient to an emergency department for an escalated level of care is largely dependent upon the appearance of the child and the severity of the likely underlying diagnosis. Any child with unstable vital signs, evidence of severe dehydration or shock, altered mental status or impaired level of consciousness, significantly abnormal laboratory values, ill appearance, or multiple injuries should be urgently transferred by emergency medical services to the nearest emergency department for further management. Transfer is also necessary for patients who fail an oral fluid challenge and are likely to require intravenous fluids to maintain hydration. Additionally, any patient who is likely to need surgical evaluation and/or intervention should be promptly transferred to an appropriate institution with available surgical services. In these cases where surgery may be required, it is prudent to withhold oral fluids in preparation for a possible procedure; providers may also consider placing a nasogastric tube to decompress the stomach and begin rehydration with isotonic fluids.

Additionally, the need for subspecialty consultation may also be an indication for transfer to the emergency department. Consultants that would need to become involved urgently include endocrinology for diabetic ketoacidosis or metabolic conditions, social work or child protective services for cases of suspected abuse or neglect, and surgical subspecialties if there are concerns for acute conditions such as appendicitis, bowel obstruction, or pyloric stenosis, among others. In contrast, there are some consults or referrals which are non-urgent and can be made on an outpatient basis. For example, consider outpatient referral to pediatric gastroenterology for cases such as suspected cyclic vomiting, gastroesophageal reflux disease, or feeding intolerance.

Discharge and Anticipatory Guidance

When considering discharge for a child with emesis, emphasis should be placed on fulfillment of discharge criteria, anticipatory guidance, and return precautions. Patients who can be safely discharged home may still be vomiting, but should be well-appearing on examination, with normal vital signs and no or minimal evidence of dehydration. They should ideally be able to demonstrate in clinic their ability to tolerate a small amount of oral fluids, and parents or caregivers should be comfortable and competent in maintaining hydration at home.

Anticipatory guidance and discharge instructions should include close follow-up with the patient's primary care provider within 24 hours, as well as directions for an appropriate diet during the remainder of the illness. Children with acute gastroenteritis should not be restricted to certain foods and should continue to be offered a normal diet, despite any ongoing vomiting, as enough food may be absorbed to help prevent dehydration. Caregivers should also offer frequent oral fluids, although if the patient has concomitant diarrhea, drinks with a high sugar content (ie, fruit juices, sodas) should be avoided as these may worsen loose stools. If a milk allergy is suspected as the cause of vomiting, parents should avoid cow's milk and milk products and might consider transitioning to a partially or fully hydrolyzed formula. Of note, the use of soy products is not routinely recommended as a first-line option in cow's milk protein allergy, particularly in infants younger than age 6 months, due to high rates of cross-allergenicity between milk protein and soy.11

Return precautions discussed with caregivers should include monitoring for increased irritability, poor feeding, decreased urine output, dry mouth, sunken eyes, inability to make tears, abdominal distention, bilious vomiting, changes in mental status, or decreased level of consciousness. Parents and caregivers should also be given contact information for any available after-hours call center or other triage phone services.


Many common infectious causes of vomiting in pediatric patients, particularly those causing gastroenteritis, can be avoided with appropriate hygiene and food-handling practices. These infections are often spread via fecal-oral transmission, making adequate handwashing a crucial step in preventing illness as well as minimizing the spread of infection to other household members and close contacts. Discussing the importance of safe water precautions with patients and families prior to traveling internationally, particularly to endemic regions, can also help prevent infection in children. In young infants, exclusive breast-feeding is the most effective way to avoid food-borne or water-borne illnesses.

Additionally, since the advent of routine vaccination against rotavirus and hepatitis A, there has been a significant decline in patients presenting with acute vomiting secondary to these pathogens.12,13 Continued encouragement of scheduled immunizations by primary care providers can further decrease the rates of infection. Other vaccines that are not routinely given in the United States, including those against typhoid, salmonella, and cholera, may be considered in appropriate patients prior to international travel based on the prevalence rates in the intended area.

And finally, another method of prevention relates to vomiting secondary to accidental ingestions and exposure to chemicals or toxins. Families and caregivers should be advised at both well-child and acute visits that they should store medications, cleaning supplies, chemicals, and other potentially dangerous substances in high cabinets or in locations that are not accessible to infants and small children. Children should be supervised closely at all times, and families should anticipate “baby-proofing” their homes prior to their infants becoming mobile.


Vomiting is a common complaint within the pediatric population and is frequently seen acutely in outpatient and inpatient settings. More often than not, children who present with abrupt-onset vomiting who are well-appearing on examination with stable vital signs are likely to have a benign, self-limiting illness. However, it is essential to perform a focused, well-informed history and thorough physical examination to recognize red flags for more serious pathologies and to sort out those children with relatively minor conditions, such as gastroenteritis, from those with more life-threatening processes, such as appendicitis or increased intracranial pressure. The age of the presenting child can be helpful in forming a concise differential diagnosis, and may also be useful when determining if a child can be safely managed at home or is at risk for potential complications and should be transferred to an emergency department or other higher level of care. Pediatric providers can and should feel empowered to perform initial testing (including laboratory studies and imaging) if warranted, and to treat common, mild to moderate illnesses in an appropriate and concise way.


  1. Hornby PJ. Central neurocircuitry associated with emesis. Am J Med. 2001;111(suppl 8A):106S–112S. doi:10.1016/S0002-9343(01)00849-X [CrossRef] PMID:11749934
  2. Lang IM, Sarna SK, Dodds WJ. Pharyngeal, esophageal, and proximal gastric responses associated with vomiting. Am J Physiol. 1993;265(5 Pt 1):G963–G972. doi:10.1152/ajpgi.1993.265.5.G963 [CrossRef] PMID:7902012
  3. Freeman R, Wieling W, Axelrod FB, et al. Consensus statement on the definition of orthostatic hypotension, neurally mediated syncope and the postural tachycardia syndrome. Clin Auton Res. 2011;21(2):69–72. doi:10.1007/s10286-011-0119-5 [CrossRef] PMID:21431947
  4. Hoffman RJ, Wang VJ, Scarfone RJ. Fleisher & Ludwig's 5-Minute Pediatric Emergency Medicine Consult. Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2012.
  5. Parashette KR, Croffie J. Vomiting. Pediatr Rev. 2013;34(7):307–319. doi:10.1542/pir.34-7-307 [CrossRef] PMID:23818085
  6. Wathen JE, MacKenzie T, Bothner JP. Usefulness of the serum electrolyte panel in the management of pediatric dehydration treated with intravenously administered fluids. Pediatrics. 2004;114(5):1227–1234. doi:10.1542/peds.2004-0457 [CrossRef] PMID:15520100
  7. Shaw KN, Bachur RG. Fleisher & Ludwig's Textbook of Pediatric Emergency Medicine. Philadelphia, PA: Wolters Kluwer; 2016.
  8. Fonseca BK, Holdgate A, Craig JC. Enteral vs intravenous rehydration therapy for children with gastroenteritis: a meta-analysis of randomized controlled trials. Arch Pediatr Adolesc Med. 2004;158(5):483–490. doi:10.1001/archpedi.158.5.483 [CrossRef] PMID:15123483
  9. Roslund G, Hepps TS, McQuillen KK. The role of oral ondansetron in children with vomiting as a result of acute gastritis/gastroenteritis who have failed oral rehydration therapy: a randomized controlled trial. Ann Emerg Med. 2008;52(1):22–29.e6. doi:10.1016/j.annemergmed.2007.09.010 [CrossRef] PMID:18006189
  10. Guarino A, Ashkenazi S, Gendrel D, Lo Vecchio A, Shamir R, Szajewska HEuropean Society for Pediatric Gastroenterology, Hepatology, and NutritionEuropean Society for Pediatric Infectious Diseases. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition/European Society for Pediatric Infectious Diseases evidence-based guidelines for the management of acute gastroenteritis in children in Europe: update 2014. J Pediatr Gastroenterol Nutr. 2014;59(1):132–152. doi:10.1097/MPG.0000000000000375 [CrossRef] PMID:24739189
  11. Agostoni C, Axelsson I, Goulet O, et al. ESPGHAN Committee on Nutrition. Soy protein infant formulae and follow-on formulae: a commentary by the ESPGHAN Committee on Nutrition. J Pediatr Gastroenterol Nutr. 2006;42(4):352–361. doi:10.1097/ [CrossRef] PMID:16641572
  12. Curns AT, Steiner CA, Barrett M, Hunter K, Wilson E, Parashar UD. Reduction in acute gastroenteritis hospitalizations among US children after introduction of rotavirus vaccine: analysis of hospital discharge data from 18 US states. J Infect Dis. 2010;201(11):1617–1624. doi:10.1086/652403 [CrossRef] PMID:20402596
  13. Wasley A, Samandari T, Bell BP. Incidence of hepatitis A in the United States in the era of vaccination. JAMA. 2005;294(2):194–201. doi:10.1001/jama.294.2.194 [CrossRef] PMID:16014593

Emesis Differential Diagnosis

System Cause
Gastrointestinal GERD, intussusception, Hirschprung's disease, gastroenteritis, celiac disease, appendicitis, pancreatitis, gallbladder disease, inflammatory bowel disease, malrotation, volvulus, constipation
Neurologic Tumor, migraine headache, meningitis, pseudotumor cerebri
Renal Obstructive uropathy, hydronephrosis, UTI, RTA
Metabolic Galactossemia, organic acidemia, urea cycle defect
Endocrine DKA, adrenal insufficiency
Respiratory Pneumonia
Other Pregnancy, eating disorder, ingestion, psychogenic

Emesis Red Flags and Diagnoses to Consider

Red Flags Consider Diagnosis
Bilious emesis Obstruction
First morning emesis Increased ICP (ie, tumor)
Hematemesis gastritis, peptic ulcer disease
Poor weight gain Celiac disease, IBD
Localized pain Appendicitis, gallbladder disease
Intermittent pain Intussusception, GERD
Polyuria, polydipsia DKA
Ill-appearing Metabolic disorder, obstruction, serious bacterial infection

Imaging and Laboratory Studies to Help Guide Diagnosis for Acute Emesis

Investigation Diagnosis
Abdominal ultrasound Intussusception, appendicitis, pyloric stenosis
Abdominal X-ray Obstruction
Upper GI series Malrotation, volvulus
Laboratory tests Serious bacterial infection
Urinalysis UTI
Urine pregnancy Pregnancy
Urine/serum toxicology Ingestion
Head CT Increased ICP

Madeline Mier, MD, is a Chief Resident in Pediatrics. Amanda Nelson, MD, is a Chief Resident in Pediatrics. Leah Finkel, MD, is the Director of Pediatrics, and an Assistant Professor of Emergency Medicine. All authors are affiliated with The University of Illinois at Chicago College of Medicine.

Address correspondence to Madeline Mier, MD, 1351 S. Halsted Street, Apartment 205, Chicago, IL 60607; email:

Disclosure: The authors have no relevant financial relationships to disclose.


Sign up to receive

Journal E-contents