General Discussion

The medical literature uses varied defining criteria for chronic and recurrent abdominal pain. Chronic abdominal pain is now usually defined as long-lasting intermittent or constant abdominal pain of at least 3 months’ duration. Recurrent abdominal pain is defined as at least three bouts of pain, severe enough to affect activities, over a period of at least 3 months. For many years, the term recurrent abdominal pain was used to describe all cases without an identified organic cause. It is now agreed that recurrent abdominal pain is a description, not a diagnosis. The exact prevalence of chronic abdominal pain is not clear, but it seems to account for 2% to 4% of all pediatric office visits, and the prevalence increases with age. In boys, the peak incidence occurs between 5 and 6 years of age, whereas girls have two peaks: one between 5 and 6 years of age and another between 9 and 10 years of age.

A complete history and physical examination are the most important components of the evaluation of any child with chronic abdominal pain. The history is used to assess possible organic causes for the abdominal pain as well as psychosocial factors that may be contributing. The HEADSS mnemonic (home life, education level, activities, drug use, sexual activity, suicide ideation/attempts) is a useful tool to screen for psychosocial problems. The history and physical examination can then be augmented by selected laboratory testing, imaging studies, and empiric therapies.

The two broad categories in the differential diagnosis for chronic abdominal pain in children are organic disorders and functional disorders. In organic disorders, physiologic, structural, or biochemical abnormalities are present. Functional disorders are conditions in which the patient has a variable combination of symptoms without an identifiable structural or biochemical abnormality and for which no specific test exists to establish the diagnosis. Functional gastrointestinal disorders recognized in childhood include functional dyspepsia, irritable bowel syndrome (IBS), functional abdominal pain, abdominal migraine, and aerophagia. The organic and functional categories are not mutually exclusive: both organic and psychological conditions can coexist and interact.

The Rome III diagnostic criteria for functional dyspepsia is defined as all of the following symptoms at least once per week for at least 2 months:

The Rome III diagnostic criteria for irritable bowel syndrome must include all of the following at least once per week for at least 2 months before diagnosis:

The Rome III diagnostic criteria for childhood functional abdominal pain must include all of the following at least once per week for at least 2 months before diagnosis:

The diagnosis of childhood functional abdominal pain syndrome must include childhood abdominal pain at least 25% of the time and one or more of the following:

The Rome III diagnostic criteria for abdominal migraine require that all of the following symptoms be present two or more times in the preceding 12 months:

The Rome III diagnostic criteria define aerophagia as at least two of the following symptoms occurring at least once per week for at least 2 months:

Causes of Chronic or Recurrent Abdominal Pain

Key Historical Features

Key Physical Findings

Suggested Work-Up

Symptom diary	A diary that includes diet, symptoms, and associated features may help to identify potential causes of the patient’s symptoms
Complete blood count (CBC) with differential	To evaluate for infection, inflammation, or anemia
Erythrocyte sedimentation	To evaluate for inflammatory processes
Urinalysis and urine culture	To evaluate for urinary tract infection or hematuria
Stool testing for occult blood	To evaluate for gastrointestinal bleeding
Pregnancy test	For girls of reproductive age

Additional Work-Up

Serum electrolytes, creatinine, blood urea nitrogen (BUN), and glucose	To evaluate for a metabolic cause for abdominal pain
Liver enzymes and amylase	To evaluate for liver disease or pancreatitis
Stool culture	If a bacterial infection is suspected
Stool testing for ova and parasites or Giardia antigen	If a parasitic or protozoal cause is suspected
Serologic testing for Helicobacter pylori	If H. pylori infection is suspected
Cultures for sexually transmitted diseases	If risk factors are present in the history or if the physical examination suggests sexually transmitted disease
Carbohydrate breath testing	To evaluate for lactose intolerance
Abdominal and pelvic ultrasonography	Ultrasound typically is one of the first imaging studies used because of its sensitivity for free fluid and the frequency of retroperitoneal disease. Ultrasound is able to inspect the ileum for Crohn’s disease as well as adenopathy and chronic features of abscess from fistulas or Meckel’s diverticulum.

Upper gastrointestinal series with small bowel follow through If chronic peptic disease or small bowel inflammatory bowel disease is suspected Abdominal computed tomography (CT) scan If extraintestinal mass lesions, abscess, or peritoneal disease are suspected, though the radiation exposure must be considered carefully Upper endoscopy Rarely indicated as a first-line investigation but useful in diagnosing eosinophilic gastritis, reflux esophagitis, H. pylori infection, Crohn’s disease, and villous injury in enteropathy Colonoscopy May be useful in the evaluation of chronic diarrhea or bleeding Barium enema Indicated primarily in the context of obstruction or chronic intussusception