Children and adults commonly suffer from recurrent abdominal (stomach) pain. One type is called irritable bowel syndrome (IBS). IBS in adults and children is one of the most common and costly health care problems in the US. Some children have pain frequently (recurrent pain) while others rarely have pain. The investigators are conducting this study to help us answer questions about the causes and treatments, and management of IBS in children.

The purpose of this study is to find out if there is more than one type of IBS in children. If there is, this will be important in deciding the best treatments. The investigators also want to learn how children with IBS differ from those who do not have recurrent abdominal (stomach) pain.

Functional gastrointestinal (GI) disorders (FGIDs), in particular irritable bowel syndrome (IBS) in adults and children, are among the most common and costly health care problems in the US. IBS disproportionately affects adult women (10-15% in western nations) and adolescent girls. Yet, health care providers remain challenged to provide effective clinical management. The etiology of IBS is not well defined and likely multi-factorial.

A Need to Define Subgroups of IBS:

This study emerges from the claim that identification of patient subgroups will advance our understanding of IBS and ultimately help develop treatment approaches. Most studies have lumped together patients with IBS into 2 groups (constipation-, diarrhea-predominant) and tested whether they differ from healthy controls. We propose that a paradigm shift is in order. We should recognize that IBS likely has multiple causes and therefore, multiple expressions. We speculate that by understanding better defined patient subgroups and linking them to newer biomarkers or tests, ultimately will further the understanding of the origins and create effective treatments.

Inclusion Criteria:

IBS:

• Age 7-12 years
• Females
• Meet criteria for irritable bowel syndrome without evidence of organic disease
• Developmentally normal
• English speaking (as the psychological measures are either not available or validated in Spanish)
• No other chronic, significant (e.g., diabetes, migraines) medical conditions
• No menses

Controls:

• Age 7-12 years
• Females
• No abdominal pain
• No GI or chronic medical conditions (e.g., diabetes)
• Developmentally normal
• English speaking (as the psychological measures are not available or validated in Spanish)
• No menses

Exclusion Criteria:

• Non-english speaking
• Developmentally or cognitively impaired
• Males
• Menses
• No mother in the household for administration of the psychological measures
• Use of any anti-depressants
• History of migraines or chronic pain disorders
• On narcotics for at least 1 week prior to enrollment
• On any NSAIDs or pain reliever for at least 24 hours prior to enrollment
• Sought psychotherapy in past 6 months for abdominal pain

We are studying only girls in this exploratory study because IBS is more common in girls than boys and the results of these studies can be compared with the results from studies of IBS in adults where the overwhelming number of patients are women.

Girls who meet the Rome III criteria for IBS or healthy girls with no complaints of stomach pain.