An adolescent with disabling abdominal pain

A previously healthy teenager was taken to a paediatric emergency department with abdominal pain, nausea, and fatigue. The pain had started four months earlier and had increased in severity and frequency, occurring daily in the past month and resulting in her missing three weeks of school and preventing her from participating in other activities. Painkillers had not helped. The results of repeated diagnostic tests were all normal, including complete blood cell count; blood and faecal inflammatory markers; renal, hepatic, and pancreatic function; urine analysis; and serial abdominal ultrasound scans. Despite repeated medical evaluations, there was no defined diagnosis. The girl reported a dull discomfort in the periumbilical area. She had no fever, vomiting, stool alteration, weight loss, nocturnal pain, or sleep problems. Her parents were concerned that this was a serious illness, given the worsening of symptoms over the past month, the lack of response to drug treatment, and the absence of a clear diagnosis. On examination, the girl appeared well, although she rated her pain 8 out of 10. Vital signs were normal and cardiorespiratory and abdominal examinations were unremarkable.