Acute abdominal pain in children

Acute abdominal pain is nontraumatic abdominal pain lasting from hours to days (usually < 7 days) and is a common symptom in children. The underlying pathology may be intra-abdominal, thoracic, or systemic. Red flags for acute abdominal pain in children (e.g., bilious vomiting, blood in stool, peritoneal signs) warrant urgent evaluation for urgent and life-threatening causes of pediatric acute abdominal pain. Diagnosis may be clinical or involve targeted evaluation. Abdominal ultrasound is the preferred initial imaging modality for most causes; abdominal x-ray is obtained for suspected bowel obstruction, bowel perforation, or foreign body ingestion. Treatment is based on the underlying etiology.

For acute abdomen in neonates, see “Differential diagnoses of neonatal intestinal obstruction.”

The causes of acute abdominal pain in children vary by age. Approximately 15% of cases are idiopathic. ^[1]

All children ^[1][2][3]

• Infections, e.g.:
  • Pediatric infectious gastroenteritis
  • Pediatric urinary tract infection
  • Pediatric pneumonia
• Pediatric GERD
• Pediatric constipation
• Sickle cell crisis

Infants and children aged < 5 years ^[1][3]

• Infantile colic
• Obstructive causes, see also, “Differential diagnoses of neonatal intestinal obstruction.”
  • Incarcerated hernia
  • Meckel diverticulum
  • Hypertrophic pyloric stenosis
  • Intestinal malrotation and volvulus
  • Hirschsprung disease
  • Intussusception
• Food-related causes
  • Cow's milk allergy
  • Food allergy
  • Lactose intolerance
• Extra-abdominal causes
  • Streptococcal pharyngitis
  • Foreign body ingestion
• Hemolytic uremic syndrome

Children 5–18 years of age ^[1][3]

• Gastrointestinal causes
  • Acute appendicitis
  • Food poisoning
  • Pediatric inflammatory bowel disease
  • Pediatric functional abdominal pain disorders
  • Peptic ulcer disease
  • Acute pancreatitis
  • Acute cholecystitis in children
  • Mesenteric adenitis
• Genitourinary causes (especially in adolescents)
  • Nephrolithiasis in children
  • Testicular torsion
  • Ovarian torsion
  • Ovarian cyst
  • Pelvic inflammatory disease
  • STIs, including pelvic inflammatory disease
  • Menstrual pain, mittelschmerz
  • Ectopic pregnancy
• Systemic causes
  • Hyperglycemic crisis
  • Infectious mononucleosis
  • IgA vasculitis

Red flags ^[1][2][4]

Any red flag suggests an urgent or life-threatening cause of pediatric abdominal pain until proven otherwise.

• Symptoms
  • Severe, persistent, and/or nocturnal pain
  • Persistent, bilious, or projectile vomiting
  • Significant GI bleeding
  • Acute or progressive constipation with other red flag symptoms
  • Concerning urinary symptoms (e.g., gross hematuria, severe flank pain, toxic appearance, oligouria or anuria)
  • Jaundice
  • Acholic stool
  • Unintentional weight loss or growth faltering
• Physical examination findings
  • Clinical features of sepsis and/or clinical features of shock
  • Peritoneal signs
  • New or progressive abdominal distension
  • Palpable mass and/or localized tenderness (e.g., abdominal, inguinal, cervical, adnexal, scrotal)
  • Absent or high-pitched bowel sounds
  • Signs of non-accidental injury to children, including child sexual abuse
• Risk factors: immunocompromised state

Approach ^[5][6]

All patients with red flags for pediatric abdominal pain should be evaluated in an emergency department or inpatient setting.

• Perform an ABCDE survey.
• Establish IV access and administer supportive care as needed, e.g.:
  • IV fluid therapy ^[7][8]
  • Analgesia (see "Pain management in children")
  • Antiemetics (see "Antiemetics in children")
• Start empiric antibiotics if infection is suspected.
  • Uncomplicated intra-abdominal infections (uIAIs): condition-specific antibiotics
  • Complicated intra-abdominal infections (cIAIs): empiric antibiotics for pediatric cIAIs
• Maintain NPO status, with possible NG decompression, until surgical need is excluded.
• Immediately consult an appropriate surgical specialist (e.g., pediatric surgery, OB/GYN) for:
  • Hemodynamic instability
  • Generalized peritoneal signs
  • Suspected surgical emergency
• Obtain initial urgent laboratory studies.
• Identify and treat the underlying condition, e.g.,
  • Consider urgent imaging and/or targeted laboratory studies (see "Diagnosis of pediatric abdominal pain).
  • Initiate condition-specific management (see "Urgent and life-threatening causes of pediatric abdominal pain").

In stable patients with an unclear diagnosis and ongoing symptoms, consider observation with serial abdominal examinations or inpatient admission. ^[5]

Do not delay the administration of analgesia, as it does not interfere with the diagnostic evaluation. ^[5][6]

Consider child maltreatment in children with severe injuries, unexplained injuries, and/or atypical pain, consider child maltreatment. ^[1]

Empiric antibiotics for pediatric complicated intra-abdominal infections ^[9][10]

• Severe illness or risk factors for hospital-acquired infection: piperacillin-tazobactam ^[9]
• Mild or moderate illness: ceftriaxone PLUS metronidazole ^[9]
• Individuals with severe penicillin allergy ^[10]
  • An aminoglycoside (i.e., gentamicin or tobramycin ) PLUS either metronidazole or clindamycin ^[9][10]
  • Ciprofloxacin PLUS metronidazole ^[9][10]

Initial urgent laboratory studies ^[1][3]

• POC glucose
• CBC with differential
• CRP and lactate
• Comprehensive metabolic panel
• Type and screen if significant bleeding is suspected and/or surgery is anticipated
• Pregnancy test for individuals who can become pregnant
• Cultures (e.g., blood, urine, stool) and urinalysis for fever or ill appearance

For critically ill patients, provide initial management for pediatric abdominal pain concurrently with clinical and diagnostic evaluation.

Focused history ^[1][2][4]

Past medical history

• Relevant family history (e.g., inflammatory bowel disease, celiac disease, diabetes mellitus)
• Developmental history (e.g., developmental screening, developmental milestones)
• Past medical history
• Dietary history
• Social history (e.g., pediatric mental and social health screening)
• Adolescents: sexual history, risk factors for STIs, screening for eating disorders

History of present illness

• Characteristics of pain, e.g.: ^[1]
  • Severity
  • Onset, duration, timing with eating
  • Location and radiation
  • Relieving or exacerbating factors
• Associated symptoms (e.g., fever, gastrointestinal symptoms)

Isolated mild to moderate nonprogressive abdominal pain is likely due to a nonurgent cause of pediatric acute abdominal pain. ^[1]

Focused examination ^[1][2][4]

• Vital signs and general appearance
• Abdominal examination, including:
  • Palpation for palpable masses and signs of peritonitis
  • Auscultation of bowel sounds
  • Examination maneuvers for appendicitis
• GU examination, as indicated
  • Males: examination of testicles and inguinal regions
  • Females: pelvic examination ^[2][4]
• Extra-abdominal examination (e.g., lung auscultation, throat examination)

Indirect assessment of pain (e.g., palpating with a stethoscope, asking the child to jump up and down and/or cough) is useful for distinguishing between voluntary and true guarding. ^[5]

Rectal and pelvic examination are not routinely indicated in children with acute abdominal pain. ^[2][5]

For critically ill patients, provide initial management for pediatric abdominal pain concurrently with clinical and diagnostic evaluation.

Approach ^[1][3]

• Many conditions can be diagnosed clinically (e.g., infectious gastroenteritis, pediatric functional constipation)
• Order targeted laboratory studies if indicated.
• If pain persists despite appropriate management, consider an ultrasound.

Targeted laboratory studies ^[1][3]

See "Initial management of pediatric abdominal pain" for initial urgent laboratory studies. Obtain appropriate studies based on suspected etiology, e.g.,:

• Hepatobiliary disease: liver chemistries
• Pancreatitis: lipase and amylase
• Risk factors for STIs, signs of PID, and/or vaginal or urethral discharge: STI screening
• Dyspepsia: H. pylori stool antigen test
• Bloody or profuse diarrhea: stool studies
• Signs of pediatric UTI: urinalysis with reflex to culture (see "Diagnostics of pediatric UTI")
• Pharyngitis: rapid strep test (if modified Centor score ≥ 2), monospot test

Imaging ^[1][3][11]

• Ultrasound
  • Abdominal ultrasound: preferred initial imaging modality for most causes of pediatric abdominal pain
  • Pelvic or transvaginal ultrasound: for suspected pregnancy (intrauterine or ectopic), ovarian torsion, or other pelvic etiologies
  • Duplex ultrasound (e.g., of scrotum, pelvis): for suspected torsion (e.g., testicular, ovarian)
• Abdominal x-ray: for suspected bowel obstruction, bowel perforation, foreign body ingestion
• CT abdomen and pelvis with IV contrast: for suspected complications and/or nondiagnostic initial imaging
• Upper GI series (fluoroscopy): for suspected midgut volvulus ^[12][13]
• Small bowel follow-through (fluoroscopy): for suspected small bowel obstruction with high risk features on x-ray ^[14]
• Diagnostic enema
  • Air enema (preferred) or water-soluble contrast enema: for suspected intussusception after initial ultrasound imaging
  • Water-soluble contrast enema for suspected Hirschsprung disease

Consider chest x-ray for all febrile patients (with or without respiratory symptoms) if an abdominopelvic etiology is not identified. ^[2]

For critically ill patients, provide initial management for red flags of pediatric acute abdominal pain.

Extra-abdominal causes

Before concluding the pain is due to an intra-abdominal cause, consider extra-abdominal causes, e.g.:

• Hyperglycemic crisis (e.g., DKA)
• Genitourinary causes of acute abdomen
  • All patients: nephrolithiasis
  • Male patients: testicular torsion
  • Female patients: ectopic pregnancy, ruptured ovarian cyst, pelvic inflammatory disease
• Pneumonia (particularly lower-lobe)
• Sickle cell crisis or splenic sequestration

Causes associated with GI obstruction

• For additional causes of GI obstruction, see:
  • “Causes of intestinal obstruction in neonates”
  • "Causes of bowel obstruction"
• An abdominal x-ray, which is often obtained initially for suspected obstruction, may show radiological signs of bowel obstruction. Condition-specific imaging is mentioned below.

Nonobstructive intra-abdominal causes

• Before concluding the pain is due to an intra-abdominal cause, consider: ^[1]
  • Extra-abdominal causes (e.g., urinary tract infection, strep throat, infectious mononucleosis)
  • Child maltreatment, especially for severe injuries, unexplained injuries, and/or atypical pain
• The following table summarizes condition-specific management of nonurgent intra-abdominal causes.
  • See "Causes of acute abdominal pain in children" for additional etiologies.
  • See "Management of common causes" for general care.

The following applies to the management of nonurgent causes of acute abdominal pain in children. ^[1][3]

• Encourage supportive care, e.g.:
  • Oral hydration
  • Nonopioid oral analgesia in children
  • Reassurance
• Initiate treatment based on suspected etiology.
• Provide clear return precautions, e.g.:
  • Symptoms persist or worsen
  • Red flags develop