There are many reasons to have a stomachache these days but with older children and adults it is easier to determine what is the cause of their pain. Children have abdominal pain occasionally but in infants it becomes a little more difficult. The causes of stomachaches in infants can be different than what may be the cause of the pain as they get older. Healthychildren.org discusses children’s stomachaches.
Constipation is often blamed for the pain. While it is rarely a problem in younger infants, constipation is a common cause of pain in children particularly when the pain is in the lower abdomen. Bowel problems are usually related to diet that is lacking fiber and fluids.
Another cause is urinary tract infection (UTI) which are more common in the 1-5 year old child, especially girls, than infants. UTI’s may produce pain in the abdomen and the bladder area, as well as burning when urinating. They may urinate frequently, have blood in their urine and may not be able to hold their urine and wet themselves. They may or may not have fever. If they have these symptoms they need to see their doctor for urine tests and appropriate antibiotics.
Strep throat along with throat pain causes abdominal pain. This is because the swallowed strep bacteria also cause irritation of the bowels. It can even cause a strep infection around the anus. The inflamed areas need to be cultured and treated with antibiotics.
Appendicitis is very rare in children under the age of 3 and uncommon under the age of 5. When a child does have appendicitis they may complain of a constant pain in the center of the abdomen. Later it moves down and over to the right side. Usually there is a loss of appetite and a resistance to walking or jumping. This too can be treated with antibiotics or may require surgery.
Exposure to lead paint, in paint chips, or toys painted with lead paint, can have symptoms of stomach ache, irritability, constipation, and even seizures. If lead exposure is a possibility, they should be tested for lead and treated.
Milk allergy is a reaction to the protein in milk and can causes cramping abdomen pain, vomiting, diarrhea and blood in the stool. Lactose intolerance can lead to pain, bloating and diarrhea.
Finally in the worrisome times with flash floods and storms, there is the stomach pain caused by emotional upsets. This pain is rarely seen before the age of 5 but with unusual stress it can happen earlier. The pain tends to come and go over a period of more than a week and seems to happen with activity that is stressful or unpleasant. There are usually no other symptoms like vomiting, diarrhea, coughing weakness, sore throat or flulike symptoms.
If a child’s pain continues or worsens over a period of 3-5 hours and if they have fever, severe sore throat or extreme change in appetite or energy level, the parent should call the doctor.
By Sally Robinson MD
University of Texas Medical Branch (UTMB)
Published 07/2025