Children's Hospital Colorado

Functional Abdominal Pain (FAP)

What is functional abdominal pain (FAP)?

Most otherwise healthy children who repeatedly complain of stomachaches for a period of two months or more have functional abdominal pain. Functional abdominal pain is not a dangerous condition, unless it is a symptom of a more severe digestive problem. But if your child is complaining of persistent pain, it is important to talk to your doctor.

The term “functional” refers to the fact that there is no blockage, inflammation or infection causing the discomfort. Nevertheless, the pain is very real, and is due to the extra sensitivity of the digestive organs, sometimes combined with changes in gastrointestinal movement patterns and toileting behavior.

Your child’s intestine has a complicated system of nerves and muscles that moves food through the digestive tract. In some children, the nerves become very sensitive and pain is experienced even during normal intestinal functions. The pain can cause your child to cry, make his/her face pale or red and cause him/her to break into a sweat. This digestive tract sensitivity can be triggered by a variety of things, such as a viral or bacterial infection, stress, or an episode of constipation. Other family members may have a history of similar problems. Because of the pain, children often stop their usual school and play activities. Fortunately, despite the recurrent episodes of pain, normal growth and general good health continue.

What causes functional abdominal pain?

The exact cause of functional abdominal pain is not known, and may vary from person to person. In some children, the nerves of the gastrointestinal tract become very sensitive and pain is experienced even when the intestines function normally. This digestive tract sensitivity can be triggered by a variety of things, such as a viral or bacterial infection, an episode of constipation or stress.

Typical stresses are school problems and family discord. Children who experience functional abdominal pain are often described as bright, sensitive and very demanding of themselves. This explains why school may be a source of stress even though the child is doing well academically and socially.

Other family members may have a history of similar problems.

Who gets functional abdominal pain?

Functional abdominal pain is very common. About 10% to 15% of school aged children will report episodes of recurrent pain. Another 15% experience pain, but do not go to the doctor for it.

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What are the signs and symptoms of functional abdominal pain?

The most common symptom is intermittent abdominal pain that occurs for at least three months. The description of the pain varies. Although it is usually located near the belly button, it can be anywhere.

The pain may be very severe, causing a child to look pale, become sweaty, cry and double over. It may be so severe that the child cannot attend school. The pain may be sharp, dull or crampy and can last minutes to hours. The pain occurs either at day or night, and the relationship to eating is unpredictable. In fact, one of the most consistent characteristics of functional abdominal pain is its inconsistency.

What tests are used to diagnose functional abdominal pain?

A history of how your child’s functional abdominal pain started will be conducted, as well as a physical exam and, if needed, basic blood, urine, stool, x-ray, endoscopyand extensive lab testing may also occur.

Why choose Children’s Hospital Colorado for functional abdominal pain testing?

If your child happens to be diagnosed with functional abdominal pain, a doctor will follow your child to see if any changes take place that would suggest a different problem is causing your child’s symptoms. From the moment you visit our hospital to the time you leave, we promise to ensure the best care for your child’s abdominal pain.

What to expect from functional abdominal testing

First your doctor will ask questions to create a detailed history of how the pain started, how it progressed, its location and other factors that can often suggest a diagnosis of functional pain. Then, he or she will do a physical exam and check your child’s growth to make sure it’s normal. In functional pain, growth is good and the physical exam is normal.

How do providers at Children’s Colorado make a diagnosis?

After the physical exam, basic blood, urine and stool tests are often performed to screen for other conditions that can cause recurrent pain, like an infection or lactose intolerance. x-rays, other imaging studies, extensive lab tests and endoscopy are only recommended for children whose history, exam or basic lab results don’t fit with the diagnosis of functional pain.

How is functional abdominal pain treated?

A woman with brown hair and wearing a white shirt smiles while listening to a patient with a stethoscope. The kid has on a red shirt and blue baseball cap.

However, for many children with functional pain, an underlying condition may never be found. Our goal at Children’s Colorado is to help you and your child resume the normal activities of childhood. If your child’s functional abdominal pain is the result of another underlying digestive disorder, like irritable bowel syndrome or lactose intolerance, pain usually goes away after addressing those conditions.

Our healthcare providers teach a variety of specific actions for handling pain episodes, such as breathing techniques that can be taught to your child. It is important to prevent the pain from becoming a reason for missing school, changing your child’s social activities or becoming the center of attention at home.

Even when the pain persists, it is reassuring to learn that this is a known condition and that it is not dangerous. Being positive about getting better will send the right signals to your child.

Why choose Children’s Hospital Colorado for your child’s functional abdominal pain?

Functional abdominal pain is a very common problem but can sometimes be a sign of a more serious gastrointestinal problem. The physicians within the Digestive Health Institute have the expertise and experience to help distinguish which children need a more extensive evaluation.


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