Acute abdominal pain


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 Perth Children’s Hospital (PCH) Emergency Department (ED) staff in the assessment and management of acute abdominal pain.


Abdominal pain is a symptom and can be due to numerous underlying aetiologies across many different organ systems.


  • Abdominal pain is a common symptom in children.
  • Serious disease may sometimes present as abdominal pain and surgical causes must be considered.
  • A thorough assessment including a history and repeated abdominal examinations is vital.
  • Abdominal pain may be an indicator for a non-organic / psychological problem  – always exclude organic causes first.


  • Acute abdominal pain is a common reason for Emergency Department presentation.
  • Most abdominal pain in children is mild and transient, and represents minor illness (e.g gastroenteritis, viral illnesses).
  • Mild intermittent, central abdominal pain is usually not serious.
  • In a small percentage of children with abdominal pain, serious medical and surgical conditions may be the underlying cause.
  • A diagnosis may be suggested by the child’s age, and other clinical features in history and examination.

Features that may suggest a serious underlying cause:

  • Increasing severity of pain, pain becoming constant, inconsolable infants.
  • Re-presentation to hospital.
  • Requiring opiate analgesia.
  • Localised pain in the abdomen.
  • Signs of peritonism.
  • Associated shock.
  • Bilious vomiting.


  • Children do not localise pain very well
  • Referred pain from an extra-abdominal cause (e.g. basal pneumonia, testicular torsion) may present as abdominal pain
  • Conversely, intra-abdominal problems may refer pain elsewhere (e.g. renal problems may present as testicular pain and sub-diaphragmatic problems may cause shoulder tip pain)
  • It may be that no formal diagnosis is found after assessment in the ED


A thorough history is essential in acute abdominal pain and can point to the possible underlying aetiology:
  • Pain pattern: character, location in the abdomen, onset, duration, constant or episodic, frequency of episodes
  • Vomiting: increasing frequency, haematemesis or bilious (dark green stained)
  • Stool pattern: constipation, diarrhoea (in gastroenteritis), incontinence (overflow in constipation)
  • Urine: decreased (in dehydration), polyuria and polydipsia (in diabetes)
  • Weight loss (diabetes, malignancy)
  • Episodes of pallor / screaming / drawing up of legs (possible intussusception)
  • Fever (infection
  • Lethargy
  • Anorexia
  • Viral features: upper respiratory tract infection – consider mesenteric adenitis
  • Urinary tract symptoms: dysuria, frequency
  • Genital pain
  • Lower respiratory tract infection symptoms: cough, grunting, respiratory distress indicating a basal pneumonia
  • Gynaecological problems: ask about menarche, menstruation pattern and associated symptoms
  • Sexual activity, use of contraception (adolescents)
  • Past surgical procedures (abdominal adhesions, bowel obstruction)
  • Other medical conditions: nephrotic syndrome, cystic fibrosis, diabetes mellitus
  • Dietary history
  • Social history: school problems, family stressors, amount of missed school, sleep pattern


  • General appearance and pain behaviour (lying very still in peritonism or very mobile in colicky pain)
  • Gait, ability to move around the bed and undress, jumping, hopping
  • Vital signs including blood pressure
  • Cardiovascular system examination
  • Respiratory examination looking for signs of pneumonia
  • Ear nose and throat examination looking for signs of infection
  • Skin rashes, lymphadenopathy
  • Abdominal examination: distension, bowel sounds, areas of tenderness (general, localised), palpable masses or faeces
  • Assess abdomen for signs of peritonism guarding, rigidity, rebound tenderness, ask the child to puff out their abdomen and suck in their abdomen
  • Abdominal palpation often needs to be done on repeat occasions to fully assess the child
  • Examine the genitalia
  • PR examinations are rarely required in children
  • Assess fluid status: dehydration, shock


  • Investigations are not required in all patients the aim of tests is to help exclude serious surgical or medical conditions
  • Most children should have a urinalysis check for glucose, ketones, haematuria, proteinuria, specific gravity, and beta-hCG (in adolescent girls)
  • Young children should have their urine sent to the laboratory for microscopy and culture (where appropriate)
  • Other investigations should only be ordered if indicated, after discussion with an Emergency Department Senior Doctor, and directed towards the possible underlying aetiology.

Investigations to consider Possible Indications
FBC Sepsis, peritonitis
Blood culture Sepsis, peritonitis
Stool microscopy and culture Bloody stools
Electrolytes, urea and creatine, Blood gas Profuse/prolonged vomiting, severe dehydration, diabetic ketoacidosis
Liver function tests Hepatitis, cholecystitis, abdominal trauma
Amylase or lipase Pancreatitis, abdominal trauma
Abdominal X-Rays Bowel obstruction, peritonitis. Constipation is not an indication
Abdominal ultrasound Pyloric stenosis, intussusception, appendicitis, gynaecological problems, cholecystitis, cholelithiaisis, renal colic, abdominal mass (possible tumour)
Abdominal CT scan Abdominal trauma, mass (possible tumour)
Initial stream urine for chlamydia and Neisseria gonorrhoea Sexually active adolescent

Differential diagnosis: conditions causing abdominal pain

Age Differential diagnosis
Neonates Infant Colic, Enterocolitis, (eg. cows milk protein induced), Pyloric Stenosis
Infants and children <2 years Viral illness, infant colic, intussusception, malrotation with volvus, mesenteric adenitis, enterocolitis (e.g. cows milk protein), haemolytic uraemic syndrome, reflux oesophagitis, Hirschsprung disease.
2-5 years Viral illness, intussusception, appendicitis, URTI (pharyngitis, tonsillitis), mesenteric adenitis, Henloch Schonlein Pupura, haemolytic uraemic syndrome, genital, testicular or ovarian torsion, pneumonia, bacterial peritonitis
>5 years Viral illness, appendicitis, URTI, (pharyngitis, tonsillitis), mesenteric adenitis, Henloch Schonlein PupuraHenloch Schonlein Pupura, genital, testicular or ovarian torsion, epididymitis, pneumonia, inflammatory bowel disease, cholelithiasis, cholecystitis, pancreatitis, urolithiasis, bacterial peritonitis, abdominal migraine, function abdominal pain
Adolescents Genital - ruptured ovarian cyst, testicular or ovarian torsion, epidydimitis, relating to menstrual cycle, sexually transmitted infections, pelvic inflammatory disease, inflammatory bowel disease, pregnancy, ectopic pregnancy, cholelithiasis, cholecystitis, pancreatitis, urolithiasis, function abdominal pain.
All children Abdominal trauma (remember non-accidental injury), gastroenteritis (viral or bacterial), constipationurinary tract infection, pyelonephritis, sepsis, diabetic ketoacidosis, bowel obstruction (e.g. abdominal adhesions), hepatitis, incarcerated hernia, malignancy (haematological or solid tumours)


Always give analgesia - this will not mask the underlying cause

Initial Management

  • If there is a possibility of a surgical cause ensure the patient is fasting.
  • Analgesia choice depends on the severity of the child’s pain.
  • Oral analgesia is appropriate in the majority of cases.
  • Opiates may be considered in severe pain.
  • Fluids if dehydrated - nasogastric or intravenous, consider IV fluid bolus.
  • If bowel obstruction is present, keep the patient fasted, insert an NGT and leave the tube on free drainage.
  • Consider anti-emetics: Ondansetron PO or IV
Consider a surgical consultation if there is:
  • Severe, persistent abdominal pain
  • Pain requiring parenteral opiate analgesia
  • Bile-stained vomiting
  • Abdominal distension
  • Peritonism
  • Localised tenderness
  • Inguinal / scrotal pain or swelling
  • Bloody stools
  • Palpable mass
  • Diagnosis is unclear.

Further management

  • Consider non pharmacological pain relief options: heat packs, distraction therapy, relaxation techniques.


Initial Analgesia options: (see Analgesia)

Drug Route
Paracetamol PO
Ibuprofen PO
Oxycodone PO
Fentanyl IN/IV
Morphine IV

Medication links are accessible within WA Health only.

Admission Criteria

  • If the diagnosis is unclear, consider a short admission for observation and analgesia. 
    • Admission may be to the Emergency Short Stay Unit or under the General Surgical Team. 
    • A joint Medical / Surgical Team admission may also be considered.
  • This will allow repeated abdominal examinations to be performed.

Discharge criteria

  • A plan for return to the ED or follow up with a local GP must be in place when sending home children with abdominal pain in which the diagnosis is not clear.


  • All observations including blood pressure must be documented on assessment:
    • Record patient’s T, P, R, BP, SpO2  (Full EDOES if clinically indicated)
    • Pain score
  • Minimum frequency hourly P, R, BP if unwell (SpO2 if clinically indicated)
  • 2/24 P, R, BP if stable and no other clinical concerns 
  • Give analgesia early
  • Apply EMLA cream if an IV cannula is likely to be required
  • Perform a urinalysis in all young children or if symptomatic.


  1. WA Health Child and Adolescent Health Service. Department of General Paediatrics. Urinary Tract Infections: Investigation and Follow Up Clinical Practice Guideline. Version 1: 2015
  2. Cameron P, Jelinek G, Everitt, I, Browne G, Raftos, editors. Textbook of Paediatric Emergency Medicine. 2nd ed. Philadelphia: Elsevier; 2011.
  3. Kliegman RM, Stanton Bonita M.D, St. Geme J, Schor NF. Nelson Textbook of Pediatrics: 20th Ed. Philadelphia: Elsevier; 2015.

Reviewer/Team: Meredith Borland (ED Director), Dennis Chow (ED Consultant), Deirdre Speldewinde (ED Consultant), Gabrielle Anstey (ED CNS), Craig Hasler (ED CNM), Kwi Moon (Senior Pharmacist)
Last reviewed: Jul 2018

Review date: Jul 2021
Endorsed by:

Drugs and Therapeutics Committee Date:  Sep 2018

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