The discomfort of RAP is typically localized in the periumbilical region and is nonradiating. In almost all other respects it is variable in character from patient to patient - often vague and ill-defined, a dull ache or a crampy feeling, but occasionally a sharp and colicky pain. It is generally mild to moderate in intensity; the child will stop playing, sit or lie down, but in a minority of affected children the pain will be sufficiently severe to cause crying. The temporal occurrence, frequency and duration of pain are also highly variable. Pain may occur at any time of the day, be reported upon awaking, or be present until the child falls asleep. However, the discomfort will only rarely awaken the child from sleep at night. The occurrence of pain generally bears no consistent relation to the ingestion of specific foods or to meals, physical activity, defecation, urination or (in girls) menstruation. Episodes may occur infrequently or several times a day, and last from a few minutes to several hours at a time. Although aggravating factors are frequently absent, a relationship between recurrent attacks of abdominal pain and stressful situations is reported in approximately one-third of affected children. A brief rest is often cited as a relieving factor. Characteristically, treatment with antacids, anticholinergics, H₂ antagonists, barbiturates and analgesics provides no consistent relief. Episodes of RAP are commonly associated with nonspecific symptoms: pallor, nausea, headaches, limb or "growing" pains and drowsiness after attacks. Sporadic vomiting may occur, but repetitive or bilious emesis should suggest the possibility of an organic disorder. Diarrhea and documented elevation of temperature are occasionally reported but are atypical, and should also suggest an alternative etiology. Characteristically, the children are otherwise well and active between episodes.

There is nothing specific or diagnostic with respect to the past or family history of the child who presents with RAP. However, as a group, the parents and siblings of children with RAP are much more likely than those of unaffected children or those with organic disease to experience somatization of stress and to provide a history of recurrent abdominal pain/irritable bowel syndrome, peptic ulcer, severe headaches and disorders that were in the past very loosely labeled as "nervous breakdown."

Except for subjective abdominal tenderness, the physical examination of children with RAP is striking in its normality. Plots of the previous and currently measured heights and weights demonstrate a normal growth velocity, and objective physical signs of disease are absent.

The intellectual abilities of children with RAP are identical to those of unaffected children, but certain personality traits are more commonly recognized in children with RAP than in those without. These children have been described as overachievers, overconscientious, high-strung, fussy or particular, anxious, and timid or apprehensive -generalizations that do not always apply in the individual case, however.

There is a close association between emotional status and function of the gastrointestinal tract, and the literature contains numerous anecdotal reports of children presenting with recurrent abdominal pain in whom there is (1) no organic cause, (2) a temporal relationship between discomfort and a specific stress, and (3) resolution of the pain in response to measures that relieve the stress. However, objective evidence of psychological difficulties - and not just the absence of an organic etiology - is necessary before a "psychogenic" label is applied. Using these criteria, psychological or emotional disturbance will be a primary diagnosis in only a very small number of children presenting with RAP.

Although the differential diagnosis of abdominal pain is extensive, a complete history and physical examination with limited laboratory investigations should enable the physician to make a positive diagnosis of recurrent abdominal pain. In 90-95% of affected children, RAP is functional; organic disease is identified in only 5-10%. The approach to diagnosis should not be one of extensive investigation to exclude organic disease. In the majority of cases of recurrent abdominal pain, the extent of appropriate investigation should be limited to a complete blood count, urinalysis, and perhaps a stool occult blood test. Comprehensive lists of organic causes of chronic abdominal pain are available but need be referred to only when features of the history and physical examination, or the CBC and urinalysis, strongly suggest an organic problem that is not readily apparent. Specific aspects of the history that should signal concern on the part of the physician include significant recurrent pain in a child under the age of 3; consistent localization of pain away from the umbilicus; frequently being woken from sleep by pain; repetitive or bilious emesis; and any constellation of symptoms and signs that are typical of a specific organic etiology.

Urogenital and alimentary disorders are the most common organic causes of RAP. Genitourinary diseases such as recurrent infection and hydronephrosis or obstructive uropathy can present with abdominal pain. In patients with these disorders who present without urinary tract symptoms, an abnormal urinalysis and pyuria will frequently bring attention to the underlying problem.

Constipation is a common disorder and patients may experience crampy abdominal discomfort in association with the urge to defecate. A suggestive history and the demonstration on physical examination of bulky stool retained in the rectum should initiate a trial of appropriate treatment.

A history of abdominal pain, bloating, flatus and watery diarrhea that occurs with heavy ingestion of "sugarless" gums or confections suggests the possibility of malabsorption of nonabsorbable carbohydrates. The same history occurring with milk intake in individuals whose ethnic background might predispose to lactase deficiency (oriental, black or peri-Mediterranean) suggests lactose malabsorption.

Pernicious vomiting or bilious emesis in the presence of abdominal pain should always alert the clinician to the possibility of an intestinal obstruction. Malrotation or incomplete rotation of the mid-gut is a disorder that may present as a bowel obstruction and also predisposes to intestinal volvulus. Whenever malrotation is suspected an upper gastrointestinal series should be performed to determine the position of the duodenojejunal flexure, and a barium enema may be required to ensure proper location of the cecum in the lower right quadrant.

Primary peptic ulcer disease is much less common in children than in adults and frequently lacks the typical meal-related characteristics that are common with the adult presentation. A family history of peptic ulcer disease, vomiting, nighttime awakening with pain, hematemesis or melena, or unexplained anemia should suggest the diagnosis.

A thorough history, careful physical examination and a minimum of laboratory examinations are essential to provide the data that allow a physician to reach a positive diagnosis of RAP. This care and thoroughness are crucial to the success of subsequent management because they demonstrate that the complaint has been seriously evaluated by the physician and lend credibility to the diagnosis that is subsequently rendered. Having made a positive diagnosis, it is then important to cease investigation and to educate and reassure the patient and parents. If this is not done the parents' perception that there is a significant probability of an underlying organic problem may be reinforced. On the other hand, reassurance in the absence of explanation (i.e., simply saying "Don't worry") is of little value.

It must be made clear that the discomfort of RAP is genuine, not imagined or manufactured for gain or manipulation. It is important to point out that this is a common complaint. Identify for the parent those criteria upon which you based the diagnosis of RAP: the periumbilical location of the discomfort, the absence of any constellation of historical or objective physical findings that suggest underlying organic disease, continued normal growth and development (show the parents the growth chart), continued general well-being between episodes, and a family history of similar functional complaints, if that exists. In those cases where they can be identified note the positive association of RAP with stressful situations or events and any characteristics of the child's personality that might serve to exaggerate the stress. Try to elicit and allay any specific concerns on the part of the child or parents (e.g., "Does my child have appendicitis?").

Encourage the parents to discuss potential stressful contributing events with the child, and recommend a positive approach to coping that includes a return to all normal activities. Insist on attendance at school. Discuss the prognosis of this condition with the parents and provide reassurance by offering to reassess the child should there be any change in the symptoms.

Patient education is generally very effective in relieving the parents' anxiety. Drugs, and specifically analgesics or sedatives, are not considered effective or appropriate. However, a recent prospective, double-blind, randomized control trial demonstrated a significant decrease in RAP in children given additional dietary fiber as compared to placebo.