Acute Abdominal Pain in Children.

Acute abdominal pain accounts for approximately 9% of childhood primary care office visits. Symptoms and signs that increase the likelihood of a surgical cause for pain include fever, bilious vomiting, bloody diarrhea, absent bowel sounds, voluntary guarding, rigidity, and rebound tenderness. The age of the child can help focus the differential diagnosis. In infants and toddlers, clinicians should consider congenital anomalies and other causes, including malrotation, hernias, Meckel diverticulum, or intussusception. In school-aged children, constipation and infectious causes of pain, such as gastroenteritis, colitis, respiratory infections, and urinary tract infections, are more common. In female adolescents, clinicians should consider pelvic inflammatory disease, pregnancy, ruptured ovarian cysts, or ovarian torsion. Initial laboratory tests include complete blood count, erythrocyte sedimentation rate or C-reactive protein, urinalysis, and a pregnancy test. Abdominal radiography can be used to diagnose constipation or obstruction. Ultrasonography is the initial choice in children for the diagnosis of cholecystitis, pancreatitis, ovarian cyst, ovarian or testicular torsion, pelvic inflammatory disease, pregnancy-related pathology, and appendicitis. Appendicitis is the most common cause of acute abdominal pain requiring surgery, with a peak incidence during adolescence. When the appendix is not clearly visible on ultrasonography, computed tomography or magnetic resonance imaging can be used to confirm the diagnosis.