A 5-year-old child presents with vomiting and escalating abdominal pain that localizes to the right lower quadrant. What is the most likely diagnosis?

• A. Inflammatory bowel disease
• B. Gastroenteritis
• C. Pancreatitis
• D. Appendicitis

Answer: (D)

Pain that begins around the middle of the abdomen and then becomes localized to the right lower quadrant reflects the way appendiceal inflammation irritates the parietal peritoneum. In a child, vomiting with escalating abdominal pain that finally localizes to the RLQ is a classic pattern for appendicitis. While other conditions can cause abdominal pain and vomiting, they don’t usually produce a focal RLQ tenderness in this setting. Inflammatory bowel disease tends to be chronic with diarrhea, weight loss, or blood in the stool; gastroenteritis often causes diffuse pain with vomiting and sometimes diarrhea rather than a precise RLQ localization; pancreatitis is rare in children and typically presents with upper abdominal pain that may radiate to the back, along with different lab findings. Thus, the combination of focal RLQ pain in a vomiting child most strongly points to appendicitis, a condition that requires prompt evaluation and often surgical management to prevent rupture.