One of the common causes of severe abdominal pain in young children is intussusception. The most common causes of abdominal pain in children are related to acute appendicitis, acute gastroenteritis, mesenteric lymphadenitis, intestinal cramps, constipation, and dietary habits. 1, intussusception. Abdominal pain is paroxysmal regular episodes, manifested as a sudden onset of severe paroxysmal colic, the child cries more than, bending knees and shrinking abdomen, pale face, lasting several minutes or more after the abdominal pain relief, quiet or sleep, after an interval of 10-20 minutes with intestinal peristalsis appears to have repeated episodes. 2, intestinal cramps. Infants are more common, there can be recurrent episodes of paroxysmal abdominal pain, abdominal distension is obvious, usually relieved after exhaustion and defecation. 3.Intestinal roundworm disease. At this time, the location of abdominal pain is not fixed, and the child has symptoms of digestive system disorders such as paranoia, heterophagia, nausea, vomiting, etc. Sometimes there are general allergic symptoms, and it is necessary to go to the hospital to check the stool and eggs. 4.Gastritis. Acute gastritis has a rapid onset, and patients only have mild loss of appetite, abdominal pain, nausea, vomiting, and in severe cases, vomiting blood, black stools, dehydration and electrolyte disorders. 5, appendicitis. Appendicitis abdominal pain characteristics of the site of pain can change, at first the location of abdominal pain is the upper abdomen and around the umbilicus, about seven or eight hours, it will shift to the right lower abdomen, the location of the right lower abdomen iliac anterior superior spine and the outer third of the line of the navel. 6. Mesenteric lymphadenitis. The earliest symptom of mesenteric lymphadenitis is abdominal pain, which is common in the right lower abdomen because the lesion mainly attacks a group of lymph nodes in the terminal ileum. The abdominal pain is variable in nature and may be vague or spasmodic, and the child feels better between pains. The possibility of acute mesenteric lymphadenitis should be considered when the child has clinical fever, abdominal pain, vomiting with upper respiratory tract infection, or occurs after intestinal inflammation without abdominal muscle tension. 7. Constipation. When the baby’s stool begins to form, baby tummy pain is common. One of the causes of constipation. If you find that your baby has fewer bowel movements than usual, especially if your baby has not had a bowel movement for more than 3 days and has a painful expression when defecating, then it is likely that you are constipated. 8, food allergies. Food allergies can cause nausea, vomiting and abdominal pain and diarrhea. If your baby has a painful stomach with bloody stools or a rash, it is likely to be a food allergy. This is the time to get medical attention. 9. Allergic purpura. There are paroxysmal abdominal pain, vomiting, blood in stool, due to edema, bleeding and thickening of the intestinal canal, sometimes a mass can be palpated in the left lower abdomen, but the majority of children have a hemorrhagic rash, swollen and painful joints, some children have proteinuria and hematuria.