Somatic referral of visceral sensations and rectal sensory threshold for pain in children with functional gastrointestinal disorders

Objective. To test the hypothesis that abdominal pain related to functional gastrointestinal disorders is associated with visceral hypersensitivity and abnormal perception of visceral sensations. Study design. We examined 35 children (10-17.6 years old) fulfilling the Rome 11 criteria with irritable bowel syndrome (IBS; n = 21), functional abdominal pain (FAP; n = 8) or functional dyspepsia (FD; n = 6) compared with 10 control subjects (10.2-16.1 years). All underwent a rectal barostat examination. Painful sensations were reported on a human body diagram. The projections of sensations induced by rectal distension, the rectal sensory threshold for pain (RSTP) and the diagnostic value of RSTP measurements were measured. Results. Rectal distension induced sensations that projected to the S3 dermatome in the control subjects and FD and to aberrant sites in children with IBS and FAP. The RSTP was decreased in children with IBS and FAP compared with control subjects (P < .002) and was not different in children with FD compared with control subjects. At 30.8 mm Hg, the 5th percentile for the control subjects the RSTP had a sensitivity rate of 89% and a specificity rate of 83% for IBS and FAP diagnosis. Conclusion. Children with IBS and FAP are characterized by the association of rectal hypersensitivity and abnormal pain referral after rectal distension.