Acute Abdominal Pain in Children

Differential Diagnosis

Common Diagnoses

Occasional Diagnoses

  • Functional/IBS
  • Stress/Malingering (e.g. School Problems, Bullying)
  • GORD in children
  • Mesenteric Adenitis
  • Cow’s Milk Protein Allergy (CMPA)
  • Muscular Strain
  • Peptic Ulcer

Rare Diagnoses

Ready Reckoner

Key distinguishing features of the most common diagnoses

ConstipationInfant ColicGastroenteritisUTI Appendicitis
Child Under 6 MonthsPossibleYesPossiblePossiblePossible
RecurrentPossibleYesNoPossibleNo
Child Acutely UnwellNoNoPossiblePossibleYes
Pain ConstantNoNoNoNoYes
Urinary SymptomsPossibleNoNoYesNo

Possible Investigations

Likely:Urinalysis, MSU.

Possible:FBC, ESR/CRP, U&E, abdominal ultrasound.

Small Print:Coeliac screen, haemoglobinopathy screen.

  • Urinalysis: Positive nitrite, leucocytes and/or blood support a clinical diagnosis of UTI; blood alone may indicate a stone (rare); urinalysis will also reveal sugar and ketones in diabetic ketoacidosis.
  • FBC: May be iron deficiency in IBD.
  • U&E: May occasionally be deranged in renal cause.
  • Abdominal ultrasound: If renal causes suspected.
  • Coeliac screen: Anti-endomysial and anti-gliadin antibodies suggest coeliac disease.
  • Haemoglobinopathy screen: If sickle cell suspected.

Top Tips

  • Be clear about safety netting – appendicitis may mimic gastroenteritis in the early stages. Share doubt and emphasise the need for reassessment if the pain becomes worse and constant, or if the general condition of the child deteriorates.
  • Don’t forget to examine the groin and testicles – strangulated hernias and torted testicles are possible causes of this presentation, and the child may be too embarrassed to indicate the site of pain or swelling.
  • Young children with less significant causes have a tendency to indicate the umbilicus as the site of pain. The further from the umbilicus the pain, the more you should consider an important cause.
  • Recurrent ‘acute’ abdominal pain presenting on Mondays may indicate a school problem.

Red Flags

  • Constant pain and the child being unable to straighten up because of discomfort suggest a surgical cause.
  • Remember the possibility of sickling in the appropriate ethnic groups.
  • Bear in mind that young children with pneumonia can present with abdominal pain – if unclear about the cause in an unwell child, check vital signs, features of respiratory distress and chest sounds.
  • Consider intussusception in the infant with apparent abdominal pain associated with bouts of screaming and pallor.

Published: 1st August 2022 Updated: 3rd April 2024

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