Abdominal pain - acute

PIC Endorsed

Key Points

Repeated examination is useful to identify the persistence or evolution of signs, and evaluate response to treatment
Appropriate analgesia should be used and will not mask potentially serious causes of pain
Investigations are guided by the most likely cause. Most children do not need investigations
Appendicitis in young children may not present with classic symptoms and can present as sepsis or perforation

Background

Abdominal pain is a common non-specific symptom that is often associated with self-limited conditions such as gastroenteritis, constipation and viral illness
The key consideration in acute abdominal pain is the differentiation between conditions which require specific or urgent management, particularly surgical management
Non-specific abdominal pain is common. Assess for red flags for other causes prior to making this diagnosis. See Abdominal pain - chronic
Symptoms in neonates may be attributed by parents as abdominal pain. A thorough examination and a broad differential should be considered in this group. Also see Unsettled baby

Causes of abdominal pain by age

	Conditions requiring urgent medical or surgical management	Other common causes
Neonates	Intussusception Necrotising enterocolitis Volvulus Incarcerated hernia Testicular torsion Sepsis Hirschsprung associated enterocolitis (HAEC)	Dietary protein allergy
Infants and children	Abdominal trauma Appendicitis (see Appendicitis in young children <5 years old under additional notes) Foreign body ingestion (eg button battery) Intussusception Pyloric stenosis Volvulus Testicular torsion Ovarian torsion Incarcerated hernia Toxin ingestion DKA Sepsis Malignancy (eg neuroblastoma, Wilms tumour)	Constipation Gastroenteritis Urinary tract infection Mesenteric adenitis Epididymitis Henoch-Schönlein purpura Hip pathology Migraine Myocarditis/pericarditis Respiratory tract infections (tonsillitis/pharyngitis, pneumonia) Hepatitis Meckel's diverticulitis
Adolescents	Abdominal trauma Appendicitis Ectopic pregnancy Ovarian cyst - torsion/rupture Testicular torsion DKA Sepsis Primary bacterial peritonitis	Constipation Gastroenteritis Urinary tract infection Cholecystitis/ Cholelithiasis Pancreatitis Hepatitis Inflammatory bowel disease Pelvic inflammatory disease Renal calculi Epididymitis Hip pathology Migraine Myocarditis/pericarditis

Assessment

History

Pain characteristics and associated symptoms (see Additional notes for causes associated with these pain characteristics)
Systemic symptoms: fever, lethargy, irritability, anorexia, weight loss
Dietary history
Stool eg diarrhoea, constipation, blood, mucus
Vomiting eg bilious, blood
Urinary symptoms eg dysuria, polyuria, polydipsia
Menstrual and sexual history in adolescents
Psychosocial history, HEADSSS in adolescents
Neonates and infants may present with persistent crying, irritability, poor feeding and lethargy, draw up legs, refusal to weight bear
Underlying medical conditions (see Additional notes for medical conditions with complications which may cause abdominal pain)

Examination

Observe the child's movements, gait, position and level of comfort
Vital signs, hydration
Abdomen

Inspect for distension, herniae, bruising
Palpate for

focal vs generalized tenderness
percussion tenderness and, if negative, rebound tenderness*
guarding or rigidity*
abdominal masses
palpable faeces

Serial examination of the abdomen is required

Examine genitalia eg for testicular torsion

Rectal or vaginal examination is rarely indicated in a child, this should be discussed with a senior clinician and if needed, should only be performed once

Assess for extra-abdominal causes (see Causes of abdominal pain by age table above)

*Peritonism:

Children will often not want to move in the bed and will be unable to walk or hop comfortably, and will have abdominal tenderness with percussion, internal rotation of the right hip can irritate an inflamed appendix

Management

Investigations

Most children need no investigations
Targeted investigation is directed by the likely differential diagnoses. These may include:

Urine analysis (+/- culture +/- pregnancy test if indicated)
LFTs eg for hepatitis
Lipase eg for pancreatitis
Venous blood gas for lactate/acidosis
Blood glucose for DKA
LFTs, lipase and UEC for abdominal injury
FBE and CRP (+/- ESR) eg for inflammatory/infectious cause such as inflammatory bowel disease
Imaging

AXR if obstruction suspected. It is not helpful in diagnosing constipation
CXR if pneumonia is suspected
Ultrasound may be requested after discussion with a senior clinician (very low yield if used indiscriminately)

It is not clinically indicated in the initial assessment for testicular torsion and may delay time critical surgery. May be requested after discussion with surgeons
Useful in suspected ovarian torsion
Useful if the history is suggestive of intussusception, even if examination is normal
May identify renal calculi

Treatment

Treatment will be guided by the likely cause

Fluid resuscitation may be required (see Intravenous fluids)
Provide adequate analgesia. IV morphine or intranasal fentanyl may be required as initial analgesia in severe pain (see Acute pain management)
Consider fasting, depending on differential diagnosis. Consider enteral or intravenous fluids if assessment or diagnosis is delayed, eg 4 hours if very young (see local fasting guidelines)
Early referral of children with possible diagnoses requiring surgical or gynaecological management
Consider a nasogastric tube if bowel obstruction is suspected

Consider consultation with local paediatric team when

Surgical cause suspected
Severe pain
Signs of peritonism
Bilious vomiting
Scrotal pain/redness and swelling
Child requiring admission

Consider transfer when

Child requires care beyond the comfort level of the local hospital.
Note: Prior to transferring infants or children with possible surgical conditions, ensure the child has adequate analgesia, venous access and intravenous fluids

For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services

Consider discharge when

There are no concerning clinical features
Presentation consistent with non-specific abdominal pain (see Abdominal pain - chronic)
A clear follow-up plan has been arranged, eg with local GP
Parents have been given advice regarding when to seek medical attention

Parent information

Abdominal pain

Additional notes

Appendicitis in young children <5 years old

Often diagnosed late in the course of illness
May not present with classical symptoms
Presentation often includes

fever, vomiting, abdominal pain
perforation or sepsis
diarrhea mimicking gastroenteritis

Requires careful attention to fluid and antibiotic management.

Causes of abdominal pain based on pain characteristics and associated symptoms

Quality	Causes
Sudden onset	Testicular or ovarian torsion/rupture Intussusception Volvulus Perforated viscus Incarcerated hernia
Episodic/colicky	Constipation Gastroenteritis Intussusception Mesenteric adenitis Ovarian torsion
Dull, increasing severity and localisation	Appendicitis

Location	Causes
Epigastric or right upper quadrant	Pancreatitis Cholecystitis Cholelithiasis Gastritis/peptic ulcer disease Pleural effusion Pneumonia
Central/periumbilical	Constipation Gastroenteritis Mesenteric adenitis Bowel obstruction Intussusception
Right lower quadrant	Appendicitis Ectopic pregnancy Ovarian cyst - torsion/rupture Intussusception Incarcerated hernia
Left lower quadrant	Constipation Ectopic pregnancy Ovarian cyst - torsion/rupture Inflammatory bowel disease Hirschsprung associated enterocolitis (HAEC) Incarcerated hernia

Associated symptoms	Causes
Bloody diarrhoea	Gastroenteritis Meckel diverticulum Inflammatory bowel disease
Bilious vomiting	Volvulus Obstruction
Polyuria, polydipsia, weight loss	DKA
Dysuria, frequency and fever	Urinary tract infection
Vomiting and diarrhoea	Gastroenteritis
Vomiting without diarrhoea	Urinary tract infection Obstruction Volvulus Ovarian torsion
Cough, fever, SOB	Pleural effusion Pneumonia

Underlying condition	Potential complications causing abdominal pain
Hirschsprung disease	Enterocolitis presents with sudden painful abdominal distension and bloody diarrhoea. children can rapidly deteriorate with dehydration, electrolyte disturbances and systemic toxicity and are at risk of colonic perforation
Cystic fibrosis
Liver disease and/or ascites	Primary bacterial peritonitis
Nephrotic syndrome
Splenectomy
VP shunt
Peritoneal dialysis
Chemotherapy	Pancreatitis
On immunosuppressants
PEG/NG/NJ fed
Inflammatory bowel disease (especially if concurrent Clostridium difficile)	Toxic megacolon
Immunocompromised	Toxic megacolon
Sickle cell disease	Vaso-occlusive crisis acute painful episodes of abdominal pain Cholecystitis
Obesity	Cholelithiasis
Spina bifida/coeliac disease	Constipation
Previous surgery	Bowel obstruction

Last updated April 2024

Reference List

D’Agostino, J. Common abdominal emergencies in children, Emergency Medicine Clinics of North America. 2002. 20 (1), 139 – 153

Jaffe DM, Reynolds SL. Diagnosing abdominal pain in a pediatric emergency department. Pediatric Emergency Care. 1992. 8 (3), 126 – 128

Leung AK, Sigalet DL. Acute abdominal pain in children. Am Fam Physician 2003; 67:2321

Radzik D, Zaramella C. Early analgesia for children with acute abdominal pain: Is it applicable without affecting diagnostic accuracy. Acute Pain. 2007. 9 (1), 48-49

Ravichandran D, Burge DM. Pneumonia presenting with acute abdominal pain in children. Br J Surg 1996; 83:1707

Reynolds SL, Jaffe DM. Diagnosing abdominal pain in a pediatric emergency department. Pediatr Emerg Care 1992; 8:126

Scholer SJ, Pituch K, Orr DP, Dittus RS. Clinical outcomes of children with acute abdominal pain. Pediatrics 1996; 98:680

Tsao K, Anderson KT. Evaluation of abdominal pain in children. https://bestpractice.bmj.com/topics/en-us/787 (viewed 14 October 2023)

The Royal Children's Hospital Melbourne

Clinical Practice Guidelines