Functional Gastrointestinal Disorders
Pain Associated Functional GI Disorders
Functional gastrointestinal disorders (FGID) are defined as recurrent symptoms (abdominal pain, diarrhea, constipation) that are as yet unexplained by structural or biochemical anomalies. Irritable bowel syndrome (IBS), functional dyspepsia (FD) and functional abdominal pain (FAP) are the most frequent painful functional disorders in children. Fifteen percent of school age children are affected by abdominal pain secondary to FGID. These disorders have more important repercussions on the quality of life of the patients than organic digestive diseases.
Our research activity has brought significant and important progress in knowledge in the field of pediatric FGID. Our research is focused on three approaches: (i) the visceral hypersensitivity approach, (ii) the biological approach and (iii) the anthropological approach.
(i) We have significantly contributed to the description, incidence and characteristics of visceral hypersensitivity in children with FGID. We have reported anomalies of viscerosomatic projections associated with the hypersensitivity in children with FGID and have been the first to prospectively measure rectal sensitivity in children with abdominal pain confirming the high incidence of visceral hypersensitivity in children. We have also provided original data on the relationship between rectal sensitivity and severity of the symptoms related to FGID. We have also paid special attention to FGID in patients with inflammatory bowel diseases.
(ii) We have been the first to perform a study on serotonin signalling in th colonic mucosa of children with IBS. We have also shown that Nerve Growth Factor content is abnormal in the colonic mucosa of in children with irritable bowel syndrome suggesting a role of this neurotrophin in FGID (funded by the CIHR and the Canadian Association of Gastroenterology).
(iii) Finally, we have collaborated with anthropologists on factors involved in the occurrence of abdominal pain.
All these projects have been funded by various foundations and by the CIHR and FRSQ.
Impedance and high Resolution manometry in functional GI disorders
Aerophagia in childhood is defined by the Rome criteria including air swallowing, abdominal distention because of intraluminal air or repetitive belching and/or flatus. We have described the multichannel intraesophageal impedance (MII) patterns in children wih aerophagia providing a tool for diagnosis of this disorder.
Diagnosis of rumination is mainly clinical and based on the Rome criteria and the main clinical feature is a painless regurgitation appearing within seconds or minutes from food/liquid ingestion. The pathophysiology of rumination remains unknown, but involves a voluntary contraction of the abdominal wall muscles with a rise in intragastric pressure (R waves) and retrograde movement of gastric contents into the esophagus. We have described the High resolution esophageal manometry pattern in children suffering from rumination that may become a diagnosis tool.