These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

Read the full PCH Emergency Department disclaimer.


To guide PCH ED staff with the assessment and management of vomiting.


  • Vomiting is one of the most common reasons for parents to take their child to see a doctor
  • Infection is the most common cause of vomiting in children, gastroenteritis being the leading cause
  • However, not all that vomits is gastroenteritis
  • Vomiting can be caused by a wide range of conditions, from the benign to the life threatening
  • Vomiting can be caused by a problem in many underlying conditions including gastrointestinal, neurological, endocrine conditions.


  • In the younger the child, vomiting may be a non-specific symptom. Therefore, vomiting in infants and young babies requires careful clinical review and consideration of a wide range of causes.
  • In infants, positing and gastro-oesophageal reflux are ‘normal’ and are only a problem if they cause pain, failure to thrive, choking or apnoea.
  • Vomiting is rarely caused by constipation alone.
  • Bilious vomiting implies bowel obstruction distal to the ampulla of Vater in the duodenum, or dynamic ileus secondary to peritonitis, sepsis etc.
  • Vomiting of fresh blood usually implies bleeding proximal to the gastric cardia.
  • Vomiting of altered blood (‘coffee ground’) implies exposure of the blood to gastric juices over a period of time.
  • Vomitus with a faecal odour is consistent with peritonitis or a low GIT obstruction,


Important elements of the history 

  • Nature of the vomiting:
    • Colour: blood or bile
    • Composition: undigested or digested food
    • Frequency and progression
    • Force: projectile?
    • Relationship to feeding and position.
  • Bowel actions: child’s usual pattern
    • When was stool last passed?
    • Diarrhoea, with blood or mucous
  • Abdominal pain
  • Abdominal distension – may suggest lower bowel obstruction
  • Infectious contacts
  • Fever
    • Suggests an infectious cause. Consider sepsis in an unwell child with fever and vomiting.
    • Vomiting in an afebrile child may indicate an serious non-infectious cause.
  • Symptoms of a Urinary tract infection (UTI) – vomiting may be the only sign in infants
  • Preceding respiratory / diarrhoeal illness – consider as a cause of intussusception
  • Cough, grunting, respiratory distress – suggesting pneumonia
  • Features of CNS infection or raised intracranial pressure
  • History of trauma (especially head and abdomen)
  • Medications possibly causing a GIT upset (e.g. antibiotics)
  • Possibility of accidental or intentional poisoning
  • Neonates – delayed passage of meconium following birth (e.g. > 48 hours after delivery), or vomiting / abdominal distension in the first 36 hours of life.
  • Need to consider food protein induced enterocolitis syndrome (FPIES) in the context of an infant who has just started on solids – did they try a new food?


  • Full general examination: cardiovascular, respiratory, ENT etc.
  • Gastrointestinal exam: careful examination of abdomen, groin in both sexes and scrotum in boys
  • CNS: specifically look for signs of raised intracranial pressure and abnormal neurological signs.


  • Pre-school children with unexplained vomiting should have a urinalysis (and urine culture if appropriate) performed to exclude urinary tract infection (UTI)
  • If abdominal trauma has occurred, presence of haematuria on urinalysis may indicate renal or urinary tract trauma
  • Special investigations should only be done after discussion with a senior emergency doctor.
Investigation Indications
FBC, CRP and blood culture Septic child – ? peritonitis
Stool microscopy and culture Septic child, blood or mucus in stools, protracted diarrhoea
UEC Profuse / prolonged vomiting
Severe dehydration

All neonates

Suspected diabetic ketoacidosis

A pale, quiet child, or one with profuse vomiting

Venous blood gas

Suspected diabetic ketoacidosis: Acidotic, profuse vomiting, IDDM with vomiting

Suspected pyloric stenosis: metabolic alkalosis

A young baby (>6 months) with repeated vomiting

A capillary gas may be sufficient in the initial instance

LFT, Lipase, Amylase Pancreatitis
Abdominal trauma
Abdominal X-Ray Any suspicion of bowel obstruction or peritonitis

Constipation is not an indication
Abdominal ultrasound
(in discussion with surgeon or Senior ED Doctor) 
Suspected pyloric stenosis
Suspected intussusception
Occasionally for suspected appendicitis
Gynaecological problems
Suspected cholecystitis/choleolithiaisis
Suspected kidney stones/renal mass

Differential diagnosis

 Causes of Vomiting by Age

Neonates and Infants Children Adolescents All Infants, Children and Adolescents
Gastro-oesophageal reflux Diabetic ketoacidosis Diabetic ketoacidosis Gastroenteritis
Pyloric stenosis Appendicitis Appendicitis Urinary tract infection, Otitis Media, Pneumonia, Sepsis
Dietary protein induced enteritis Oesophagitis Psychogenic, eating disorder URTI: tonsillitis, pharyngitis
Intussusception Cyclical vomiting syndrome Cyclical vomiting syndrome GIT obstruction: malrotation with volvulus
Hirschsprung disease   Gastric ulcer Hepatobiliary, pancreatic disease
Metabolic disorders   Pregnancy Adrenal crisis, metabolic disorders
Sepsis / Urinary tract infection (UTI)   Testicular torsion Poisoning – toxic ingestion, self harm
      Central nervous system infection (e.g. meningitis), increased intracranial pressure (e.g. malignancy), head injury


  • If shocked, correct with IV boluses of 20mL/kg of 0.9% Sodium Chloride and repeat if required. More information: Intravenous fluid therapy
  • If gastroenteritis is the cause of vomiting, manage as per Gastroenteritis guideline
  • Consider referral to the general surgical team if there is:
    • bile stained vomiting
    • bloody stools (unless explained by a medical cause such as bacterial enterocolitis)
    • abdominal distension
    • signs of peritonism: guarding, rebound tenderness, localised abdominal tenderness
    • palpable abdominal mass
    • inguinoscrotal / testicular pain or swelling (hernia)
    • diagnosis unclear (unless trivial symptoms in a well child).
  • Correct dehydration and electrolyte abnormalities (e.g. hypokalaemia) as necessary
  • If bowel obstruction is present, keep fasted, insert a nasogastric tube and leave the tube on open drainage.


  • The use of anti-emetic medications such as ondansetron (dose 0.1 to 0.15mg/kg sublingual or IV) should not be routinely used, but can be considered in:
  • Use of anti-emetic medications such as metoclopramide and prochlorperazine are not recommended for children because of a significant risk of serious extra-pyramidal side effects and dystonic reactions.1


  1. Lewis K, O’Day CS, Dystonic Reactions, NCBI StatPearls Publishing LLC 2021, Dystonic Reactions - StatPearls - NCBI Bookshelf (nih.gov)


  1. Textbook of Emergency Medicine 2nd edition, A Holland  565-570,222-224
  2. Central neurocircuitry associated with emesis. Hornby PJ Am J Med. 2001;111 Suppl 8A:106
  3. Abdominal surgical emergencies in infants and young children. McCollough M, Sharieff GQ Emerg Med Clin North Am. 2003;21(4):909.

Endorsed by:  Co-Director, Surgical Services  Date:  Oct 2021

 Review date:   Oct 2024

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