Abstract
BACKGROUND & AIMS: Pharmacologic treatments for irritable bowel syndrome (IBS) and medical management of symptoms are increasingly based on IBS subtype, so it is important to accurately differentiate patients. Few studies have classified subtypes of pediatric IBS, and conclusions have been challenged by methodologic limitations. We performed a prospective study to investigate the distribution of IBS subtypes among children and adolescents based on stool diary information, and compared subtypes according to demographic and pain characteristics. METHODS: We studied 129 subjects, ages 7 to 18 years (mean age, 11.4 ± 2.8 y; 60.5% female; 69.0% white) who met Pediatric Rome III IBS criteria and were part of larger studies of children with functional gastrointestinal disorders, recruited from primary and tertiary care centers. Children completed daily pain and stool diaries for 2 weeks. Participants were assigned IBS subtypes based on their reported stool information per adult Rome III criteria. IBS subtypes were compared for demographic variables and pain characteristics. RESULTS: IBS with constipation was the most common subtype of the disorder (58.1% of subjects), whereas mixed IBS was the least common (2.3% of subjects); 34.1% of subjects were unsubtyped IBS and 5.4% had IBS with diarrhea. The groups of different IBS subtypes did not differ significantly by sex, age, ethnicity, or pain characteristics. CONCLUSIONS: In contrast to adults, in children, IBS with constipation and unsubtyped IBS are the most common subtypes, whereas IBS with diarrhea and mixed IBS are less common. Demographic and pain characteristics cannot distinguish subtypes.