Epidemiological and pathophysiological aspects of abdominal pain predominant functional gastrointestinal disorders in children and adolescents: a Sri Lankan perspective

Abdominal pain-predominant functional gastrointestinal disorders (AP-FGIDs) are a worldwide pediatric problem with uncertain pathology. Main objectives of this thesis were to assess epidemiology, risk factors and underlying pathophysiological mechanisms of AP-FGIDs. A systematic review and meta-analysis revealed a wide variation in prevalence of IBS in Asian children (2.8% to 25.7%). An epidemiological study in Sri Lankan children revealed AP-FGIDs in 12.5%. Irritable bowel syndrome (IBS) was the commonest AP-FGID. Constipation-predominant, diarrhea-predominant and mixed IBS had equal distributions. Intestinal and extra-intestinal symptoms were common in affected children. Recognized risk factors for AP-FGIDs were female sex, exposure to stressful life events and physical, sexual and psychological abuse. Another study revealed lower HRQoL scores for physical, emotional, social and school functioning in teenagers with AP-FGIDs. Their healthcare consultation was 28%. The symptoms associated with healthcare consultation were abdominal bloating and vomiting. The lower HRQoL was an important determinant of healthcare consultation. This was more than the severity of symptoms. Using ultrasound, four studies have shown decreased gastric emptying and antral motility in children with all four types of AP-FGIDs, functional abdominal pain (FAP), IBS, functional dyspepsia (FD) and abdominal migraine (AM). Gastric emptying negatively correlated with severity of symptoms in FAP, FD and AM. Children with IBS exposed to emotional stress had a significantly lower gastric emptying rate. The relationship between abnormal motility and emotional stress suggests the possibility of altered brain-gut functions in pathogenesis