Functional abdominal pain refers to recurrent abdominal pain and is one of the most common childhood and adolescent complaints. The vast majority of children and adolescents with recurrent abdominal pain have "functional" or "non-organic" pain, meaning that the pain is not caused by physical abnormalities. Patients usually fall into one of two categories:
Most pediatric GI specialists believe that the pain is caused by abnormal contractions in the intestines and overly sensitive nerves in the GI tract. The perception of pain is thought to involve input from both the nerves in the GI tract and the processing of these signals from the brain. As a result, psychological stress, anxiety or depression may provoke pain episodes but they may also occur without an obvious cause.
Children with functional abdominal pain usually have pain that is located at or around the belly button and have no other warning signals to suggest a more serious cause. Some warning signals in children with recurrent abdominal pain that usually require additional testing include:
Although often not necessary for most children with recurrent abdominal pain, testing may include a urinalysis, complete blood count (CBC), erythrocyte sedimentation rate (ESR - a marker for inflammation), stool cultures (for parasites and bacteria), and/or a stool test for blood. Further testing, if required, may include an x-ray, upper GI, abdominal (and/or pelvic) ultrasound or CT scan, or endoscopy.
North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition - NASPGHAN.org