A 9-year-old girl arrived at my pediatric practice recently complaining of a stomachache. Over the past 12 months, she had come in numerous times with abdominal distress. Sometimes the pain was associated with a sore throat — in which case I had to make sure it was not caused by a strep throat — at other times with diarrhea due to a viral infection. But this time, as was often the case, there was nothing in the medical history or even medical tests that suggested why her stomach hurt. Everything was normal.

Then we looked at a diary her mother had been keeping at my request to track her daughter’s eating and bathroom habits, and to see if there was any psychological link to the pain. It quickly became clear that the girl’s recurrent stomachaches were related to stress from school. Once the girl understood the connection and was able to talk about the stress, her pain subsided considerably, and I have seen her less often.

The problem

Stomachaches account for numerous visits to pediatricians’ offices. Parents often worry that a kidney infection or appendicitis is responsible for the pain. Although serious disorders can cause abdominal pain, stomachaches in kids are usually due to something less worrisome, such as food issues, constipation or stress, especially at the start of the school year.

Abdominal pain can be broadly divided into two types. Acute pain has been present for less than a week. It can come on suddenly or can build slowly over the course of a day. Pediatricians see children with this type of pain every day. The problem is often caused by a simple viral infection, the “stomach flu” or even strep throat. Recurrent pain, on the other hand, has been present off and on for weeks, months or years. Ten to 15 percent of school-aged children will seek medical care for recurrent abdominal pain.

Most cases of recurrent abdominal pain are caused by stress, constipation or lactose intolerance, in which a person’s digestive system cannot process a sugar found in dairy products. Diets that include lots of foods with high-fructose corn syrup bother some. Some drugs, such as the anti-inflammatory medication ibuprofen, can cause abdominal pain, though it occurs less often in children than adults. More serious causes of recurrent abdominal pain, such as celiac disease, ulcerative colitis and Crohn’s disease, are less common in a general pediatric setting.

Making a diagnosis

When doctors see children with recurrent pain, they start with a detailed medical history because that often suggests a diagnosis. For example, it is important for parents to check the frequency and consistency of a child’s bowel movements because adults are usually unaware of what goes on in the bathroom after their children are toilet trained.

Pain that occurs more often during the week than on weekends or holidays is likely to have a stress component. However, weekends are not necessarily stress-free. Children may still have to deal with sports, religious school or family issues such as parental separation or divorce.