Subtypes of irritable bowel syndrome in children: Prevalence at diagnosis and at follow-up

Objectives To assess the prevalence of irritable bowel syndrome (IBS) subtypes in childhood at diagnosis and their changes over 1 year. Study design This is an observational, prospective, multicenter study. Consecutive pediatric patients with IBS, according to Rome III criteria, were enrolled over a 1-year period. Parents recorded weekly stool frequency and consistency and gastrointestinal and extraintestinal symptoms in a diary. Stool consistency was scored according to the Bristol Stool Form Scale. Children were evaluated after 2, 3, 6, and 12 months. Results We enrolled 100 children with IBS (median age 9.9 years, range 4.2-16.7 years, 52 girls and 48 boys). At time of enrollment, constipation-IBS was the prevalent subtype (45%), with a prevalence of girls at 62% (P <.005); diarrhea-IBS was reported in 26% of children, with a prevalence of boys at 69% (P <.005); and alternating-IBS was described in 29% of children, without a difference between sexes. During the follow-up, 10% of patients changed their IBS subtypes at 2 months, 9% at 3 months, 7% at 6 months, and 6.3% at 12 months. Twenty-four percent of patients changed IBS subtype between the time of enrollment and 12 months. Conclusions Constipation-IBS is the prevalent subtype in children, with a higher frequency in girls. In boys, diarrhea-IBS is the most common subtype. It is important to acquire knowledge about IBS subtypes to design clinical trials that may eventually shed new light on suptype-specific approaches to this condition.