Common causes of abdominal pain in babies and toddlers include:

• Stomach flu (gastroenteritis).
• Gas from overfeeding or milk intolerance.
• Constipation.
• Spitting up.

Less common causes of abdominal pain in this age group include:

• Injury to the abdomen.
• Inguinal hernia.
• Bladder infections (urinary tract infections).

Uncommon causes of abdominal pain in this age group include:

• Appendicitis. Abdominal pain before age 2 is rarely caused by appendicitis.
• Intussusception.
• Hirschsprung's disease.
• Lead poisoning.
• Malrotation.
• Pyloric stenosis.