Heart Rate Variability in Children With a Functional Gastrointestinal Disorder
Heart Rate Variability in Children With a Functional Gastrointestinal Disorder
The current study is designed to assess relationships between anxiety/stress, autonomic
 nervous system balance, and electrical activity in the stomach before and after
 eating/drinking in children with abdominal pain.
Chronic or recurrent abdominal pain in children is a very common complaint in children and
 adolescents, and is most often associated with the presence of a functional gastrointestinal
 disorder (FGID). It is likely that the clinical symptoms in FGIDs are the result of an
 interaction between biologic, psychologic, and social factors. The psychologic factor most
 implicated is chronic stress or anxiety. Stress may influence gastrointestinal function and
 symptoms through altering the balance of the autonomic nervous system (ANS). Imbalance in the
 ANS has potential effects on gastrointestinal mechanosensitivity, motor function (e.g.
 stomach emptying and accommodation), and electrical rhythms. All of these can be associated
 with abdominal pain. Theory and early evidence from studies done with healthy adult
 populations suggest that ANS imbalance can reduce the body's ability to respond electrically
 to food/water consumption. However, the relationships between chronic stress/anxiety, ANS
 balance/imbalance, and electrical activity in the stomach before and after eating/drinking
 remain to be fully explored in children with FGIDs. The current study is a two-part pilot
 study designed to assess these relationships. Part I involves assessment of anxiety/stress
 (i.e., BASC parent- and self-reports) along with ANS balance (i.e., heart rate variability)
 and electrical activity in the stomach (i.e., electrogastrography) measured in the fasting
 state and following a test meal. Part II involves the same assessments with rapid water
 loading replacing the test meal. Results will be analyzed by specific FGID, as well as for
 the group as a whole. We expect to enroll 75 children ages 8-17 in each part, including 30
 healthy controls and 45 children with an FGID. Elucidating these relationships is a necessary
 first step in developing more effective treatments for children with recurrent abdominal pain
 and, ultimately, reducing the personal and societal costs of this common pain entity.
Inclusion Criteria:

 -  Ages 8 - 17 years

 -  Evaluated in Abdominal Pain Clinic at Children's Mercy Hospital or the
 Gastroenterology Clinic at Children's Mercy South for abdominal pain of at least 8
 weeks duration and fulfilling symptom-based criteria for FD, IBS, or FD/IBS.

 Exclusion Criteria:

 -  Previous abdominal surgery

 -  Chronic disease requiring regular medical care (e.g. gastrointestinal diseases,
 diabetes mellitus, juvenile rheumatoid arthritis, cystic fibrosis, cancer).

 -  Non-English speaking

 NOTE: Control subjects will meet all patient inclusion/exclusion criteria except for
 Inclusion Criteria #2. Control subjects will be excluded for history of abdominal pain,
 nausea, vomiting, diarrhea, constipation, or bloating.