 Probiotics play an important role in preventing overgrowth of potentially pathogenic bacteria and maintaining the integrity of the gut mucosal barrier. The beneficial effects of probiotics have been previously studied in adult patients with IBS. Even though most of the studies demonstrate efficacy, other studies do not support these observations. Few studies addresses the efficacy of probiotics in children with IBS. The goal of the present study was to determine whether oral administration of the probiotic Lactobacillus GG under randomized, double-blind, placebo-controlled conditions would improve symptoms of children with abdominal pain. 