Functional gastrointestinal diseases in children: Facing the rising tide


  • Financial support: None.
  • Potential competing interests: None.


Dr Shaman Rajindrajith, Department of Paediatrics, Faculty of Medicine, University of Kelaniya, Thalagolla Road, Ragama 11010, Sri Lanka. Email:

Functional gastrointestinal disorders (FGDs) are a collection of conditions in which recurrent gastrointestinal symptoms occur without discernible organic pathology. In its latest iteration, the Rome Group classifies FGDs in children and adolescents into nine major disorders. These include functional dyspepsia, irritable bowel syndrome (IBS), functional abdominal pain, abdominal migraine, aerophagia, adolescent rumination syndrome, cyclic vomiting syndrome, functional constipation, and functional non-retentive fecal incontinence.[1] In view of the remarkably high prevalence, recurrent nature of symptoms, and lack of well-established management strategies, FGDs pose a formidable challenge to practicing pediatricians.

A paper from Sagawa and colleagues in this issue of the journal reports a study on epidemiology and quality of school life (QoSL) of children with FGDs in Japan. It provides insightful details of high prevalence (14%) of FGDs in Japanese school children and documents the deleterious effects of FGD on QoSL.[2] Results of the study highlight a growing public health problem in Asia in the new millennium, demanding our undivided attention.

The prevalence of FGDs in children has increased dramatically across Asia during the past decade. There is mounting evidence to indicate that these conditions are becoming a significant regional health issue. A study evaluating the whole spectrum of FGDs in school children of 10–16 years has shown a remarkably high prevalence of 29%.[3] Common FGDs reported in Asian children are IBS and functional constipation. Series of studies across the continent have reported IBS ranging from 4.1% in Iranian school children to 26% in Korean girls.[4, 5] In China, the country with the largest population in the world, 13–21% of school children are suffering from IBS.[6, 7] The prevalence of functional constipation is also on the rise. Two studies have shown exceptionally high prevalence of functional constipation in the industrialized areas of Asia, such as Hong Kong (12.2%) and Singapore (29.8%).[8, 9] Similarly, several studies from our group have also shown IBS (10%), functional constipation (15%), aerophagia (7%), functional dyspepsia (2.5%), functional abdominal pain (4.4%), and abdominal migraine (1%) in Sri Lankan school-aged children.[10-13] This “bird's-eye view” of data clearly shows that FGDs are rapidly increasing in both developed and developing nations of Asia. It is also more disturbing to note that these rates reported from Asia are way above those reported from the West, where FGDs were previously thought to be more prevalent.

The pathophysiology of most of the FGDs is still far from clear. Primarily, visceral hypersensitivity and abnormal motility are proposed as main contributory factors for abdominal pain-predominant FGDs, such as IBS and functional dyspepsia. In addition, IBS is well known to follow gastrointestinal infections (postinfectious IBS), which are a major health problem in many developing nations in Asia. Abnormal colorectal motor functions and sensitivity are also considered to be the pathophysiological mechanisms for constipation.

Modifiable risk factors such as diets low in fiber, increased consumption of junk foods, and adoption of sedentary lifestyles are known to predispose children to develop constipation.[8, 14] Childhood obesity is another significant risk factor, especially for defecation disorders such as constipation and fecal incontinence.[15] With changing standards of living and urbanization, these factors are becoming increasingly common in the Asian region.

Moreover, the biology and pathophysiology of FGDs have increasingly been shown to be associated with psychological stress and early adverse life events, both common occurrences in Asian communities. Stressful life events, both school and home related, are well known to predispose children to develop many FGDs such as aerophagia, IBS, functional dyspepsia, functional abdominal pain, and defecation disorders.[11-13] Psychological disturbances such as depression have been shown to be associated with IBS in adolescents.[6] In addition, we have previously shown that constipation is common among children living in war-torn areas.[16] Schools across Asia have a highly competitive education system, competition being triggered by the lack of opportunities and parental/peer pressure, leading to high level of stress among students. In addition, civil unrest is sweeping across several areas in the region. These factors could also contribute to sustain the higher occurrence of FGDs in Asia, and require further study.

Despite these glaring facts, current diagnosis and management of FGDs in children are not optimal. There is poor awareness of FGDs among primary care physicians and pediatricians in the region. Children are often labeled as having “gastritis” or “psychological problems” instead of trying to make a definitive diagnosis and arriving at possible etiologies. To compound matters further, there is no consensus across the globe on how to investigate children with FGDs. Pediatric endoscopy services are not widely available in many Asian countries and other specialized investigations, such as barostat and gastrointestinal motility studies, are only available in tertiary care research centers which are not accessible to most of the children suffering from FGDs. Furthermore, there are no large-scale randomized controlled trials to establish evidence-guided treatment for FGDs. Some of the trials conducted in the West have failed to show significant benefits of commonly used therapeutic options such as tricyclic antidepressants[17] and high-fiber diets[18] in FGDs. Treatment options like psychotherapy, guided imagery, and biofeedback are difficult to implement due to the lack of trained personnel and scarce resources. Finally, due to the ever present and insurmountable workload faced by the clinicians, there is a significant reduction in the consultation time that is needed to manage FGDs, a condition by its very nature requiring more time to explore its roots and possible therapeutic approaches. Therefore, it is inevitable that childhood FGDs are poorly managed across the region.

The World Health Organization has stressed the fact that health is not a mere absence of disease; physical, social, and emotional well-being are also integral parts of the concept of health.[19] Although FGDs do not contribute directly to child mortality, poor management strategies would invariably lead to a series of deleterious ramifications including poor physical, social, and emotional well-being and disruption of education. Although there is mounting evidence that FGDs affect health-related quality of life (HRQoL) in adults,[20] the understanding of interactions between childhood FGDs and HRQoL still remains in its infancy.

Varni et al. have studied HRQoL in children with IBS and compared them with children having organic gastrointestinal diseases. This study has clearly shown that children with IBS have lower quality of life in physical, emotional, social, and school functioning.[21] Using similar methods, Youssef and colleagues have also reported poorer HRQoL in children with functional constipation compared with that of children with gastroesophageal reflux and inflammatory bowel disease.[22] Another study on children with slow transit constipation has reported similar results.[23] All three studies have clearly identified the impact of FGDs on school performance in children.

Long-standing symptoms, the recurrent nature of the disorder, and associated psychological consequences are likely to influence poor HRQoL in children with FGDs, even though precise mechanisms have not been elucidated. In addition, symptoms such as fecal incontinence are socially unacceptable, lead to rejection by peers, and thereby promote social isolation.[24] Reduction of physical, mental, and social functioning ultimately affects school performance, creating a vicious cycle of psychological stress, aggravation of symptoms, and spiralling down of HRQoL. Interference with QoSL is commonly associated with poor education outcomes which invariably lead to poor earning capacity as adults. This would ultimately turn out to be an added burden to the society at large.

This brings us back to the key findings of the paper by Sagawa and coworkers. They have shown a significantly lower QoSL in children with FGDs. FGDs such as cyclic vomiting syndrome and aerophagia, which were previously thought to be uncommon, have also contributed to significant reduction in QoSL. These findings seem to ring an early warning bell regarding the impact of FGDs on school performance of affected children. The findings of this study should be taken seriously by all interested stakeholders, including school and health authorities, clinicians, parents, and policy-makers. Awareness programs, expansion of facilities, improvement of man power, including specialized training, are needed to be implemented sooner than later to deal with the abysmally dark and ominously rising tide of FGDs in Asian children.