2 year old baby tummy ache causes more, common gastritis, constipation and other internal diseases and intussusception, hernia and other surgical diseases. 1. internal disease: 2-year-old baby stomach pain is more common cause of acute gastritis, may be caused by infection, may also be eaten things are not clean, the baby in addition to stomach pain, there will be vomiting, diarrhea and other manifestations. 2-year-old baby’s gastrointestinal function is not perfect, and sometimes constipation can also cause baby stomach pain. 2. Surgical disease: 2-year-old baby if it is sudden severe abdominal pain, and there is vomiting and bloody stool, it may be intussusception. If the baby has a hernia, it can also cause tummy ache. If your baby has a tummy ache in the lower right abdomen, it could be appendicitis. Whichever the cause of tummy ache in a 2 year old baby, it is advisable to take the baby to the hospital for examination and treatment of the symptoms.