Abdominal pain is a very common presentation in children and has a very long list of causes. A detailed history and examination are required to distinguish between the causes. In exams, specific features and associations help you identify the underlying cause.
Causes
Causes of acute abdominal pain include:
- Urinary tract infection (suprapubic pain associated with dysuria and urinary frequency and urgency)
- Pyelonephritis (loin/back pain associated with fever, nausea and vomiting)
- Gastroenteritis (generalised abdominal pain associated with fever, vomiting and diarrhoea)
- Appendicitis (central abdominal pain spreading to the right iliac fossa)
- Mesenteric adenitis (associated with a recent upper respiratory tract infection)
- Intussusception (colicky, non-specific abdominal pain with redcurrant jelly stools)
- Bowel obstruction (pain, distention, absolute constipation and vomiting)
- Testicular torsion (sudden-onset, unilateral testicular pain, nausea and vomiting)
Causes of chronic abdominal pain include:
- Functional abdominal pain (where no cause is found to explain the pain)
- Constipation (associated with infrequent hard stools and straining)
- Gastro-oesophageal reflux (worse after feeding or eating)
- Peptic ulcers and H. Pylori infection (epigastric pain associated with dyspepsia and nausea)
- Infantile colic (infants less than 6 months of age)
- Abdominal migraine (episodic central abdominal pain with associated symptoms)
- Coeliac disease (associated with failure to thrive, bloating and loose stools)
- Inflammatory bowel disease (associated with loose stools, rectal bleeding and weight loss)
- Irritable bowel syndrome (associated with bowel habit and stool abnormalities)
- Tumours (e.g., neuroblastoma or Wilms tumour)
Systemic illnesses that can be associated with abdominal pain include:
- Henoch-Schonlein purpura (associated with a non-blanching rash on the legs and buttocks)
- Diabetic ketoacidosis (associated with polyuria, polydipsia and weight loss)
- Cystic fibrosis (associated with recurrent respiratory tract infections and greasy stools)
- Sickle cell anaemia (e.g., splenic sequestration crisis)
Gynaecological causes to consider in adolescent girls:
- Dysmenorrhea (period pain)
- Mittelschmerz (ovulation pain)
- Ectopic pregnancy (pregnancy implanted outside the uterus, particularly the fallopian tubes)
- Pelvic inflammatory disease (pelvic infection, often by sexually transmitted organisms)
- Ovarian cysts
- Ovarian torsion (twisting of the fallopian tube and vessels associated with an ovary)
Red Flags
Key red flags suggesting a serious underlying cause include:
- Persistent or bilious vomiting (bowel obstruction)
- Severe chronic diarrhoea (inflammatory bowel disease)
- Fever (appendicitis or gastroenteritis)
- Rectal bleeding (inflammatory bowel disease)
- Weight loss or faltering growth (inflammatory bowel disease, coeliac disease or malignancy)
- Dysphagia (difficulty swallowing can indicate a blockage in the oesophagus)
- Abdominal mass on examination (tumour)
Initial Investigations
Initial investigations that may indicate the pathology:
- Positive urine dipstick indicates a urinary tract infection
- Anaemia can indicate inflammatory bowel disease or coeliac disease
- Raised inflammatory markers (ESR and CRP) can indicate inflammatory bowel disease
- Raised anti-TTG or anti-EMA antibodies indicate coeliac disease
- Raised faecal calprotectin indicates inflammatory bowel disease
Recurrent Abdominal Pain
Recurrent abdominal pain describes when a child presents with repeated episodes of abdominal pain without a clear cause. When no disease process is present, the pain may be described as non-organic or functional. This is common and can lead to psychosocial problems, such as missed days at school and parental anxiety. There is overlap between recurrent abdominal pain, functional abdominal pain and irritable bowel syndrome.
Recurrent abdominal pain often corresponds to stressful life events, such as the loss of a relative or bullying. The theory for the pathophysiology is increased sensitivity and inappropriate pain signals from the visceral nerves (the nerves in the gut) in response to normal stimuli. This is called visceral hypersensitivity.
Management of recurrent abdominal pain involves careful explanation and reassurance. Measures to help manage the pain include:
- Distracting the child from the pain with other activities or interests
- Encourage parents not to ask about or focus on the pain
- Address psychosocial triggers and exacerbating factors
- Support from a school counsellor or child psychologist
Last updated February 2025
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