Local tenderness + McBurney's point rigidity most reliable clinical sign
History
Vomiting
Irritability/lethargy
Physical
Abdominal distention
Vomiting
Irritability/lethargy
Abdominal distention
History
Vomiting
Abdominal pain
Fever
Physical
Diffuse abdominal tenderness
Localized RLQ TTP occurs <50%
Vomiting
Abdominal pain
Fever
Diffuse abdominal tenderness
Localized RLQ TTP occurs <50%
Localized RLQ TTP occurs <50%
History
Vomiting (often precedes pain)
Abdominal pain
Fever
Anorexia
Physical
RLQ tenderness
Vomiting (often precedes pain)
Abdominal pain
Fever
Anorexia
RLQ tenderness
History
Vomiting
Abdominal pain
Fever
Anorexia
Physical
RLQ tenderness
Vomiting
Abdominal pain
Fever
Anorexia
RLQ tenderness
Present similar to adults
RLQ pain
Vomiting (occurs after onset of abdominal pain)
Anorexia
RLQ pain
Vomiting (occurs after onset of abdominal pain)
Anorexia
Appendicitis 
Emergent
Cervicitis
Necrotizing Enterocolitis
Uvulitis
Volvulus
Orchitis
Testicular torsion