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.

Allergies, stress and constipation can cause recurrent abdominal pain. (istockphoto)
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.

Symptoms that increase the chances that a serious problem could be causing the pain include recurrent vomiting, diarrhea or weight loss; pain that wakes a child up from sleep; and pain that is not located in the middle of the abdomen — that is, around the belly button. In these cases, a doctor will often order blood, urine and stool tests as well as an abdominal X-ray and sonogram. If more follow-up is needed, the child may be referred to a specialist.

But most of the time, the stomachaches that bring a child into a doctor’s office can be handled with a few changes to diet or routine.

Lactose intolerance

Lactose is the sugar found in milk, cheese, yogurt and other dairy products. Lactase, the chemical that is needed to break down lactose and make it digestible, is made in the upper part of the small intestine, but some people don’t make it. For them, any lactose they eat or drink pass esundigested into the large intestine. There, bacteria consume it and release byproducts that can make a person feel sick. Symptoms of lactose intolerance include nausea, stomachache, belching, loose bowel movements and excessive gas.

Lactose intolerance is not an all-or-nothing phenomenon. Some people can handle small amounts of lactose. With other people, any amount of lactose will make them sick.

The best way to treat lactose intolerance is to avoid milk sugar. Most people do this by drinking lactose-free milk, which is available in most grocery stores. Lactase supplements can also be taken before ingesting milk products. Another option is to replaced milk, ice cream and other products with substitutes made only from non-milk sources such as soy, rice or almonds.


I have been a pediatrician for more than 25 years, and three things continue to surprise me. First, large numbers of people suffer from constipation. According to Benny Kerzner, emeritus chief of pediatric gastroenterology at Children’s National Medical Center, 25 percent of referrals to specialists like him are for constipation. Second, most people do not realize that constipation is a common cause of abdominal pain. Third, constipation manifests itself in unsuspected ways.

People with constipation may pass large, hard bowel movements once or twice a week or lots of small “rabbit pellets” every day. Some people experience constipation regularly while others have it once in a while. Some people with constipation have no symptoms other than having to work hard when they go to the bathroom. Others may feel bloated or have a stomachache for days before they go. Constipation can come on gradually or so suddenly a person may double over in pain. It is not uncommon for parents to rush their child to an emergency room because they thought the abdominal pain was due to appendicitis.

Very few medical conditions cause constipation in children. Most of the time, it occurs because of dietary factors or insufficient water intake, or because the problem runs in the family.

Foods that cause constipation include milk products and processed grains (white bread, pasta, rice). Some people have problems if they eat apples or bananas. (Many nutrition experts say only unripe bananas are the problem.)

For stomachaches caused by constipation, opt for foods that are high in fiber, drink plenty of liquids, get lots of exercise (which gets things moving through the large intestine) and don’t delay going to the bathroom when the need strikes.

There are also a number of medications that can help if diet changes don’t. Parents should talk to their doctor before using any medication.


Everyone has to deal with stress. Fortunately, people and animals are equipped with the tools they need to fight or run away, depending on which strategy seems most likely to succeed. This is called the fight-or-flight response. This response does not just kick in when some extremely stressful situation is imminent.

The day-to-day stress that people deal with — worrying about bills, worrying about interacting with peers in school — can trigger a variation of this response. It is less intense, but it lasts longer. And the same biological reactions that would give a person extra strength in dangerous situations can produce symptoms when facing ordinary stress: rapid heart rate; feeling tense, nervous or queasy; getting a stomachache; and having sweaty palms.

A good way to explain this phenomenon to children is to ask them if they have ever gotten butterflies in their stomach before a soccer game or when they had to speak in front of their classmates.

Stress causes abdominal pain when the nerves in a person’s intestinal tract overreact to the normal process of digesting food and pushing waste out of the body. Two additional facts are important regarding stress-induced abdominal pain. First, the situation that causes the stress does not always occur when the person is having pain. Second, even though stress is the trigger, the pain is very real.

Dealing with stress-induced abdominal pain is trickier than managing constipation or lactose intolerance. In general, eating a healthful diet is important, and in some people, taking probiotics can help reduce pain. These other steps can help:

●Learn some deep breathing techniques, which have been shown to help people calm down. There are CDs specifically for children that can help walk you through the process of breathing and then relaxing your body. Many yoga classes also provide breathing training for older chldren.

●Try to figure out where the stress is coming from by talking to your child about school, friends, home, etc. Talk to your pediatrician to get guidance on how to address the problem.

●Consult mental health professionals if stress-induced stomach aches do not respond to suggestions from your pediatrician.

Bennett is a pediatrician in Washington, author of “Max Archer, Kid Detective: The Case of the Recurring Stomachaches” and a regular contributor to KidsPost. His Web site, www.howardjbennett.com, includes a blog on common pediatric problems.