Relation Between Clinical Symptoms and Experimental Visceral Hypersensitivity in Pediatric Patients With Functional Abdominal Pain

Abstract

The association between clinical symptoms and laboratory visceral sensitivity remains poorly defined and controversial. It has even been suggested that laboratory observations of visceral sensitivity are irrelevant to the clinical presentation of chronic visceral pain. To better understand this association, gastrointestinal and psychological features of pediatric patients' clinical presentation were examined in relation to a laboratory-based measure of visceral sensitivity. At the time of their medical evaluation, 101 patients with medically unexplained abdominal pain (ages 8-15 years) completed validated questionnaires assessing recent depressive symptoms, functional disability, pain efficacy beliefs, gastrointestinal (GI), and non-GI symptoms. These clinical features were examined in relation to visceral sensitivity assessed 2 months later in the laboratory. The measure of visceral sensitivity was based on increases in GI complaints in response to the water load symptom provocation task. More severe GI symptoms and functional disability in the weeks before patients' clinical evaluation were associated with significantly greater increases in GI symptoms in the laboratory in response to the water load symptom provocation task (all P < 0.04). Patients believing that they had the ability to alleviate their pain (high problem-focused pain efficacy) had significantly lower laboratory visceral sensitivity (P < 0.01). Clinical depressive symptoms and non-GI symptoms were not associated with laboratory visceral sensitivity. Clinical presentations of more severe GI symptoms and disability as well as low perceived pain efficacy are significant predictors of laboratory visceral sensitivity in children with functional abdominal pain. Depression does not account for the association between clinical presentation of GI symptoms and a laboratory measure of visceral sensitivity.