| Neonate | 1 month to 2 years | 2 to 5 years | >5 years |
| Adhesions* Necrotizing enterocolitis* Volvulus* Colic¶ Dietary protein allergy Testicular torsion | Adhesions* Foreign body ingestion* Hemolytic uremic syndrome* Hirschsprung disease* Incarcerated hernia* Intussusception* Trauma (including inflicted injury)* Gastroenteritis¶ Viral illness¶ Dietary protein allergy Hepatitis Inflammatory bowel disease Meckel's diverticulum Sickle cell syndrome vasoocclusive crisis Toxin Tumor Urinary tract infection | Adhesions* Appendicitis* Foreign body ingestion* Hemolytic uremic syndrome* Intussusception* Primary bacterial peritonitis* Trauma (including inflicted injury)* Gastroenteritis¶ Viral illness¶ Pharyngitis¶ Constipation¶ Henoch Schönlein purpura Hepatitis Inflammatory bowel disease Intraabdominal abscess Meckel's diverticulum Urinary tract infection Ovarian torsion Pancreatitis Pneumonia Sickle cell syndrome vasoocclusive crisis Toxin Tumor | Adhesions* Appendicitis* Diabetic ketoacidosis* Hemolytic uremic syndrome* Myocarditis, pericarditis* Perforated ulcer* Primary bacterial peritonitis* Trauma* Constipation¶ Gastroenteritis¶ Pharyngitis¶ Viral illness¶ Abdominal migraine Cholecystitis or cholelithiasis Familial Mediterranean fever Gastrointestinal dysmotility Henoch Schönlein purpura Hepatitis Inflammatory bowel disease Intraabdominal abscess Meckel's diverticulum Ovarian torsion Pancreatitis Pneumonia Acute porphyria (adolescents) Ruptured ovarian cyst Sickle cell syndrome vasoocclusive crisis Testicular torsion Urinary tract infection Urolithiasis |
